Handling empty fields

[Xero]

Hello. I am using Visual Studio .NET (Academic Edition) to write a VB
program. My computer is running Win XP Pro.

I am writing a calculator and requires users to enter two numbers. After
entering the numbers, they should click a button called 'Display Results'.
How can I display a dialog box prompting the users to check their entry if
they left any of the boxes empty? I have tried the .IsNaN function but in
vein.

Thanks.
--
Xero

http://www.chezjeff.net
My personal web portal

[Peter Proost]

Hi,

check if isnumeric(textbox.text)
or for the length you could check textbox.text.length > 0
or combine them

hth
Peter
"Xero" <jeff@chezjeff(REMOVE).net> wrote in message
news:F8**********************************@microsof t.com...

Hello. I am using Visual Studio .NET (Academic Edition) to write a VB
program. My computer is running Win XP Pro.

I am writing a calculator and requires users to enter two numbers. After
entering the numbers, they should click a button called 'Display Results'.
How can I display a dialog box prompting the users to check their entry if
they left any of the boxes empty? I have tried the .IsNaN function but in
vein.

Thanks.
--
Xero

http://www.chezjeff.net
My personal web portal

[Cor Ligthert]

Xero,

To show the result from Peters actions when not
messagebox.show("You should enter something")

I hope this helps?

Cor
"Xero" <jeff@chezjeff(REMOVE).net>
....

Hello. I am using Visual Studio .NET (Academic Edition) to write a VB
program. My computer is running Win XP Pro.

I am writing a calculator and requires users to enter two numbers. After
entering the numbers, they should click a button called 'Display Results'.
How can I display a dialog box prompting the users to check their entry if
they left any of the boxes empty? I have tried the .IsNaN function but in
vein.

Thanks.
--
Xero

http://www.chezjeff.net
My personal web portal

[Xero]

I see. Thanks very much.

"Peter Proost" wrote:

Hi,

check if isnumeric(textbox.text)
or for the length you could check textbox.text.length > 0
or combine them

hth
Peter
"Xero" <jeff@chezjeff(REMOVE).net> wrote in message
news:F8**********************************@microsof t.com...

Hello. I am using Visual Studio .NET (Academic Edition) to write a VB
program. My computer is running Win XP Pro.

I am writing a calculator and requires users to enter two numbers. After
entering the numbers, they should click a button called 'Display Results'.
How can I display a dialog box prompting the users to check their entry if
they left any of the boxes empty? I have tried the .IsNaN function but in
vein.

Thanks.
--
Xero

http://www.chezjeff.net
My personal web portal

[Xero]

Eh ... sorry, I still have some problem ...
I copied the line of code but it didn't work out.

Could you post the exact line of code? I want to display the message 'One of
the boxes is empty.' if any of the two boxes named as 'num1' and 'num2' is
left empty. Thanks again.

"Peter Proost" wrote:

Hi,

check if isnumeric(textbox.text)
or for the length you could check textbox.text.length > 0
or combine them

hth
Peter
"Xero" <jeff@chezjeff(REMOVE).net> wrote in message
news:F8**********************************@microsof t.com...

Hello. I am using Visual Studio .NET (Academic Edition) to write a VB
program. My computer is running Win XP Pro.

I am writing a calculator and requires users to enter two numbers. After
entering the numbers, they should click a button called 'Display Results'.
How can I display a dialog box prompting the users to check their entry if
they left any of the boxes empty? I have tried the .IsNaN function but in
vein.

Thanks.
--
Xero

http://www.chezjeff.net
My personal web portal

[Peter Proost]

Here are 2 possible pieces of code, place it behind the click event of a
button, or where you want to check the textboxes

<<<<<<<code 1>>>>>>

If Not IsNumeric(num1.Text) Or Not IsNumeric(num2.Text) Then
MsgBox("one of the boxes is empty")
End If

<<<<<<code 1>>>>>>

<<<<<<code 2>>>>>>

Dim blnOk As Boolean
If Not IsNumeric(num1.Text) Then
blnOk = False
MsgBox("Box one is empty")
Else
blnOk = True
End If
If Not IsNumeric(num2.Text) Then
blnOk = False
MsgBox("Box two is empty")
Else
blnOk = True
End If

If blnOk Then
'execute the rest of the code
MsgBox("They're both filled")
End If

<<<<<<code 2>>>>>>>>

greetz Peter

"Xero" <jeff@chezjeff(REMOVE).net> wrote in message
news:C0**********************************@microsof t.com...

Eh ... sorry, I still have some problem ...
I copied the line of code but it didn't work out.

Could you post the exact line of code? I want to display the message 'One of the boxes is empty.' if any of the two boxes named as 'num1' and 'num2' is
left empty. Thanks again.

"Peter Proost" wrote:

Hi,

check if isnumeric(textbox.text)
or for the length you could check textbox.text.length > 0
or combine them

hth
Peter
"Xero" <jeff@chezjeff(REMOVE).net> wrote in message
news:F8**********************************@microsof t.com...

Hello. I am using Visual Studio .NET (Academic Edition) to write a VB
program. My computer is running Win XP Pro.

I am writing a calculator and requires users to enter two numbers. After entering the numbers, they should click a button called 'Display Results'. How can I display a dialog box prompting the users to check their entry if they left any of the boxes empty? I have tried the .IsNaN function but in vein.

Thanks.
--
Xero

http://www.chezjeff.net
My personal web portal

[Xero]

Sorry but they don't work either.
The code 'num1.Text' is underlined by a blue line, saying that 'Text is not
a member of Double.'
Sorry that I forgot to tell you that both num1 and num2 are of data type
'Double'.

"Peter Proost" wrote:

Here are 2 possible pieces of code, place it behind the click event of a
button, or where you want to check the textboxes

<<<<<<<code 1>>>>>>

If Not IsNumeric(num1.Text) Or Not IsNumeric(num2.Text) Then
MsgBox("one of the boxes is empty")
End If

<<<<<<code 1>>>>>>

<<<<<<code 2>>>>>>

Dim blnOk As Boolean
If Not IsNumeric(num1.Text) Then
blnOk = False
MsgBox("Box one is empty")
Else
blnOk = True
End If
If Not IsNumeric(num2.Text) Then
blnOk = False
MsgBox("Box two is empty")
Else
blnOk = True
End If

If blnOk Then
'execute the rest of the code
MsgBox("They're both filled")
End If

<<<<<<code 2>>>>>>>>

greetz Peter

"Xero" <jeff@chezjeff(REMOVE).net> wrote in message
news:C0**********************************@microsof t.com...

Eh ... sorry, I still have some problem ...
I copied the line of code but it didn't work out.

Could you post the exact line of code? I want to display the message 'One

of

the boxes is empty.' if any of the two boxes named as 'num1' and 'num2' is
left empty. Thanks again.

"Peter Proost" wrote:

Hi,

check if isnumeric(textbox.text)
or for the length you could check textbox.text.length > 0
or combine them

hth
Peter
"Xero" <jeff@chezjeff(REMOVE).net> wrote in message
news:F8**********************************@microsof t.com...
> Hello. I am using Visual Studio .NET (Academic Edition) to write a VB
> program. My computer is running Win XP Pro.
>
> I am writing a calculator and requires users to enter two numbers. After > entering the numbers, they should click a button called 'Display Results'. > How can I display a dialog box prompting the users to check their entry if > they left any of the boxes empty? I have tried the .IsNaN function but in > vein.
>
> Thanks.
> --
> Xero
>
> http://www.chezjeff.net
> My personal web portal

[Peter Proost]

is it a windows forms application?

grtz Peter
"Xero" <jeff@chezjeff(REMOVE).net> wrote in message
news:D9**********************************@microsof t.com...

Sorry but they don't work either.
The code 'num1.Text' is underlined by a blue line, saying that 'Text is not a member of Double.'
Sorry that I forgot to tell you that both num1 and num2 are of data type
'Double'.

"Peter Proost" wrote:

Here are 2 possible pieces of code, place it behind the click event of a
button, or where you want to check the textboxes

<<<<<<<code 1>>>>>>

If Not IsNumeric(num1.Text) Or Not IsNumeric(num2.Text) Then
MsgBox("one of the boxes is empty")
End If

<<<<<<code 1>>>>>>

<<<<<<code 2>>>>>>

Dim blnOk As Boolean
If Not IsNumeric(num1.Text) Then
blnOk = False
MsgBox("Box one is empty")
Else
blnOk = True
End If
If Not IsNumeric(num2.Text) Then
blnOk = False
MsgBox("Box two is empty")
Else
blnOk = True
End If

If blnOk Then
'execute the rest of the code
MsgBox("They're both filled")
End If

<<<<<<code 2>>>>>>>>

greetz Peter

"Xero" <jeff@chezjeff(REMOVE).net> wrote in message
news:C0**********************************@microsof t.com...

Eh ... sorry, I still have some problem ...
I copied the line of code but it didn't work out.

Could you post the exact line of code? I want to display the message 'One

of

the boxes is empty.' if any of the two boxes named as 'num1' and

'num2' is left empty. Thanks again.

"Peter Proost" wrote:

> Hi,
>
> check if isnumeric(textbox.text)
> or for the length you could check textbox.text.length > 0
> or combine them
>
> hth
> Peter
> "Xero" <jeff@chezjeff(REMOVE).net> wrote in message
> news:F8**********************************@microsof t.com...
> > Hello. I am using Visual Studio .NET (Academic Edition) to write a VB > > program. My computer is running Win XP Pro.
> >
> > I am writing a calculator and requires users to enter two numbers.

After

> > entering the numbers, they should click a button called 'Display

Results'.

> > How can I display a dialog box prompting the users to check their

entry if

> > they left any of the boxes empty? I have tried the .IsNaN function

but in

> > vein.
> >
> > Thanks.
> > --
> > Xero
> >
> > http://www.chezjeff.net
> > My personal web portal
>
>
>

[Xero]

Yes, it is.

"Peter Proost" wrote:

is it a windows forms application?

grtz Peter
"Xero" <jeff@chezjeff(REMOVE).net> wrote in message
news:D9**********************************@microsof t.com...

Sorry but they don't work either.
The code 'num1.Text' is underlined by a blue line, saying that 'Text is

not

a member of Double.'
Sorry that I forgot to tell you that both num1 and num2 are of data type
'Double'.

"Peter Proost" wrote:

Here are 2 possible pieces of code, place it behind the click event of a
button, or where you want to check the textboxes

<<<<<<<code 1>>>>>>

If Not IsNumeric(num1.Text) Or Not IsNumeric(num2.Text) Then
MsgBox("one of the boxes is empty")
End If

<<<<<<code 1>>>>>>

<<<<<<code 2>>>>>>

Dim blnOk As Boolean
If Not IsNumeric(num1.Text) Then
blnOk = False
MsgBox("Box one is empty")
Else
blnOk = True
End If
If Not IsNumeric(num2.Text) Then
blnOk = False
MsgBox("Box two is empty")
Else
blnOk = True
End If

If blnOk Then
'execute the rest of the code
MsgBox("They're both filled")
End If

<<<<<<code 2>>>>>>>>

greetz Peter

"Xero" <jeff@chezjeff(REMOVE).net> wrote in message
news:C0**********************************@microsof t.com...
> Eh ... sorry, I still have some problem ...
> I copied the line of code but it didn't work out.
>
> Could you post the exact line of code? I want to display the message 'One of
> the boxes is empty.' if any of the two boxes named as 'num1' and 'num2' is > left empty. Thanks again.
>
> "Peter Proost" wrote:
>
> > Hi,
> >
> > check if isnumeric(textbox.text)
> > or for the length you could check textbox.text.length > 0
> > or combine them
> >
> > hth
> > Peter
> > "Xero" <jeff@chezjeff(REMOVE).net> wrote in message
> > news:F8**********************************@microsof t.com...
> > > Hello. I am using Visual Studio .NET (Academic Edition) to write a VB > > > program. My computer is running Win XP Pro.
> > >
> > > I am writing a calculator and requires users to enter two numbers.
After
> > > entering the numbers, they should click a button called 'Display
Results'.
> > > How can I display a dialog box prompting the users to check their
entry if
> > > they left any of the boxes empty? I have tried the .IsNaN function but in
> > > vein.
> > >
> > > Thanks.
> > > --
> > > Xero
> > >
> > > http://www.chezjeff.net
> > > My personal web portal
> >
> >
> >

[Peter Proost]

when do you place the entered values in the double variables?

I propbably wont be able to reply anymore untill tomorrow

grtz peter

"Xero" <jeff@chezjeff(REMOVE).net> wrote in message
news:F9**********************************@microsof t.com...

Yes, it is.

"Peter Proost" wrote:

is it a windows forms application?

grtz Peter
"Xero" <jeff@chezjeff(REMOVE).net> wrote in message
news:D9**********************************@microsof t.com...

Sorry but they don't work either.
The code 'num1.Text' is underlined by a blue line, saying that 'Text is

not

a member of Double.'
Sorry that I forgot to tell you that both num1 and num2 are of data

type 'Double'.

"Peter Proost" wrote:

> Here are 2 possible pieces of code, place it behind the click event of a > button, or where you want to check the textboxes
>
> <<<<<<<code 1>>>>>>
>
> If Not IsNumeric(num1.Text) Or Not IsNumeric(num2.Text) Then
> MsgBox("one of the boxes is empty")
> End If
>
> <<<<<<code 1>>>>>>
>
> <<<<<<code 2>>>>>>
>
> Dim blnOk As Boolean
> If Not IsNumeric(num1.Text) Then
> blnOk = False
> MsgBox("Box one is empty")
> Else
> blnOk = True
> End If
> If Not IsNumeric(num2.Text) Then
> blnOk = False
> MsgBox("Box two is empty")
> Else
> blnOk = True
> End If
>
> If blnOk Then
> 'execute the rest of the code
> MsgBox("They're both filled")
> End If
>
> <<<<<<code 2>>>>>>>>
>
> greetz Peter
>
>
>
> "Xero" <jeff@chezjeff(REMOVE).net> wrote in message
> news:C0**********************************@microsof t.com...
> > Eh ... sorry, I still have some problem ...
> > I copied the line of code but it didn't work out.
> >
> > Could you post the exact line of code? I want to display the message 'One

> of
> > the boxes is empty.' if any of the two boxes named as 'num1' and

'num2' is

> > left empty. Thanks again.
> >
> > "Peter Proost" wrote:
> >
> > > Hi,
> > >
> > > check if isnumeric(textbox.text)
> > > or for the length you could check textbox.text.length > 0
> > > or combine them
> > >
> > > hth
> > > Peter
> > > "Xero" <jeff@chezjeff(REMOVE).net> wrote in message
> > > news:F8**********************************@microsof t.com...
> > > > Hello. I am using Visual Studio .NET (Academic Edition) to

write a VB

> > > > program. My computer is running Win XP Pro.
> > > >
> > > > I am writing a calculator and requires users to enter two

numbers. > After
> > > > entering the numbers, they should click a button called 'Display > Results'.
> > > > How can I display a dialog box prompting the users to check their > entry if
> > > > they left any of the boxes empty? I have tried the .IsNaN

function but

> in
> > > > vein.
> > > >
> > > > Thanks.
> > > > --
> > > > Xero
> > > >
> > > > http://www.chezjeff.net
> > > > My personal web portal
> > >
> > >
> > >
>
>
>

[Xero]

Perhaps I should post the lines of code of the event handlier the 'Display
Result' button. Thanks again.

'*******************************
'Begin of code

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles Button1.Click
Dim num1 As Double
Dim num2 As Double
num1 = TextBox1.Text
num2 = TextBox2.Text
If reverse.Checked = False Then
If s.Checked Then
MsgBox("The sum of the numbers " & num1 & " and " & num2 & "
is " & num1 + num2 & ".", MsgBoxStyle.Information)
End If
If d.Checked Then
MsgBox("The difference of the numbers " & num1 & " and " &
num2 & " is " & num1 - num2 & ".", MsgBoxStyle.Information)
End If
If m.Checked Then
MsgBox("The multiple of the numbers " & num1 & " and " &
num2 & " is " & num1 * num2 & ".", MsgBoxStyle.Information)
End If
If q.Checked Then
MsgBox("The quotient of the numbers " & num1 & " and " &
num2 & " is " & num1 / num2 & ".", MsgBoxStyle.Information)
End If
End If
If reverse.Checked = True Then
If s.Checked Then
MsgBox("The sum of the numbers " & num1 & " and " & num2 & "
is " & num2 + num1 & ".", MsgBoxStyle.Information)
End If
If d.Checked Then
MsgBox("The difference of the numbers " & num1 & " and " &
num2 & " is " & num2 - num1 & ".", MsgBoxStyle.Information)
End If
If m.Checked Then
MsgBox("The multiple of the numbers " & num1 & " and " &
num2 & " is " & num2 * num1 & ".", MsgBoxStyle.Information)
End If
If q.Checked Then
MsgBox("The quotient of the numbers " & num1 & " and " &
num2 & " is " & num2 / num1 & ".", MsgBoxStyle.Information)
End If
End If
If (s.Checked = False) And (d.Checked = False) And (m.Checked =
False) And (q.Checked = False) Then
MsgBox("No operation key has been selected. Please try again.",
MsgBoxStyle.Exclamation, "Calculator")
End If
End Sub

'End of code
'*******************************
"Peter Proost" wrote:

when do you place the entered values in the double variables?

I propbably wont be able to reply anymore untill tomorrow

grtz peter

"Xero" <jeff@chezjeff(REMOVE).net> wrote in message
news:F9**********************************@microsof t.com...

Yes, it is.

"Peter Proost" wrote:

is it a windows forms application?

grtz Peter
"Xero" <jeff@chezjeff(REMOVE).net> wrote in message
news:D9**********************************@microsof t.com...
> Sorry but they don't work either.
> The code 'num1.Text' is underlined by a blue line, saying that 'Text is not
> a member of Double.'
> Sorry that I forgot to tell you that both num1 and num2 are of data type > 'Double'.
>
> "Peter Proost" wrote:
>
> > Here are 2 possible pieces of code, place it behind the click event of a > > button, or where you want to check the textboxes
> >
> > <<<<<<<code 1>>>>>>
> >
> > If Not IsNumeric(num1.Text) Or Not IsNumeric(num2.Text) Then
> > MsgBox("one of the boxes is empty")
> > End If
> >
> > <<<<<<code 1>>>>>>
> >
> > <<<<<<code 2>>>>>>
> >
> > Dim blnOk As Boolean
> > If Not IsNumeric(num1.Text) Then
> > blnOk = False
> > MsgBox("Box one is empty")
> > Else
> > blnOk = True
> > End If
> > If Not IsNumeric(num2.Text) Then
> > blnOk = False
> > MsgBox("Box two is empty")
> > Else
> > blnOk = True
> > End If
> >
> > If blnOk Then
> > 'execute the rest of the code
> > MsgBox("They're both filled")
> > End If
> >
> > <<<<<<code 2>>>>>>>>
> >
> > greetz Peter
> >
> >
> >
> > "Xero" <jeff@chezjeff(REMOVE).net> wrote in message
> > news:C0**********************************@microsof t.com...
> > > Eh ... sorry, I still have some problem ...
> > > I copied the line of code but it didn't work out.
> > >
> > > Could you post the exact line of code? I want to display the message 'One
> > of
> > > the boxes is empty.' if any of the two boxes named as 'num1' and
'num2' is
> > > left empty. Thanks again.
> > >
> > > "Peter Proost" wrote:
> > >
> > > > Hi,
> > > >
> > > > check if isnumeric(textbox.text)
> > > > or for the length you could check textbox.text.length > 0
> > > > or combine them
> > > >
> > > > hth
> > > > Peter
> > > > "Xero" <jeff@chezjeff(REMOVE).net> wrote in message
> > > > news:F8**********************************@microsof t.com...
> > > > > Hello. I am using Visual Studio .NET (Academic Edition) to write a VB
> > > > > program. My computer is running Win XP Pro.
> > > > >
> > > > > I am writing a calculator and requires users to enter two numbers. > > After
> > > > > entering the numbers, they should click a button called 'Display > > Results'.
> > > > > How can I display a dialog box prompting the users to check their > > entry if
> > > > > they left any of the boxes empty? I have tried the .IsNaN function but
> > in
> > > > > vein.
> > > > >
> > > > > Thanks.
> > > > > --
> > > > > Xero
> > > > >
> > > > > http://www.chezjeff.net
> > > > > My personal web portal
> > > >
> > > >
> > > >
> >
> >
> >

[Peter Proost]

Hi, this code should do the trick

<<<<<<<<<<code>>>>>>>>>>>>

Dim num1 As Double
Dim num2 As Double
Dim blnOk As Boolean = True
If Not IsNumeric(TextBox1.Text) Then
blnOk = False
MsgBox("Box one is empty")
Else
num1 = TextBox1.Text
blnOk = True
End If
If Not IsNumeric(TextBox2.Text) Then
blnOk = False
MsgBox("Box two is empty")
Else
num2 = TextBox2.Text
blnOk = True
End If

If blnOk Then
If reverse.Checked = False Then
If s.Checked Then
MsgBox("The sum of the numbers " & num1 & " and " & num2
& " is " & num1 + num2 & ".", MsgBoxStyle.Information)
End If
If d.Checked Then
MsgBox("The difference of the numbers " & num1 & " and "
& num2 & " is " & num1 - num2 & ".", MsgBoxStyle.Information)
End If
If m.Checked Then
MsgBox("The multiple of the numbers " & num1 & " and " &
num2 & " is " & num1 * num2 & ".", MsgBoxStyle.Information)
End If
If q.Checked Then
MsgBox("The quotient of the numbers " & num1 & " and " &
num2 & " is " & num1 / num2 & ".", MsgBoxStyle.Information)
End If
End If
If reverse.Checked = True Then
If s.Checked Then
MsgBox("The sum of the numbers " & num1 & " and " & num2
& " is " & num2 + num1 & ".", MsgBoxStyle.Information)
End If
If d.Checked Then
MsgBox("The difference of the numbers " & num1 & " and "
& num2 & " is " & num2 - num1 & ".", MsgBoxStyle.Information)
End If
If m.Checked Then
MsgBox("The multiple of the numbers " & num1 & " and " &
num2 & " is " & num2 * num1 & ".", MsgBoxStyle.Information)
End If
If q.Checked Then
MsgBox("The quotient of the numbers " & num1 & " and " &
num2 & " is " & num2 / num1 & ".", MsgBoxStyle.Information)
End If
End If
If (s.Checked = False) And (d.Checked = False) And (m.Checked =
False) And (q.Checked = False) Then
MsgBox("No operation key has been selected. Please try
again.", MsgBoxStyle.Exclamation, "Calculator")
End If
End If

<<<<<<<<<code>>>>>>>>

greetz Peter
"Xero" <jeff@chezjeff(REMOVE).net> wrote in message
news:C3**********************************@microsof t.com...

Perhaps I should post the lines of code of the event handlier the 'Display
Result' button. Thanks again.

'*******************************
'Begin of code

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles Button1.Click
Dim num1 As Double
Dim num2 As Double
num1 = TextBox1.Text
num2 = TextBox2.Text
If reverse.Checked = False Then
If s.Checked Then
MsgBox("The sum of the numbers " & num1 & " and " & num2 & " is " & num1 + num2 & ".", MsgBoxStyle.Information)
End If
If d.Checked Then
MsgBox("The difference of the numbers " & num1 & " and " &
num2 & " is " & num1 - num2 & ".", MsgBoxStyle.Information)
End If
If m.Checked Then
MsgBox("The multiple of the numbers " & num1 & " and " &
num2 & " is " & num1 * num2 & ".", MsgBoxStyle.Information)
End If
If q.Checked Then
MsgBox("The quotient of the numbers " & num1 & " and " &
num2 & " is " & num1 / num2 & ".", MsgBoxStyle.Information)
End If
End If
If reverse.Checked = True Then
If s.Checked Then
MsgBox("The sum of the numbers " & num1 & " and " & num2 & " is " & num2 + num1 & ".", MsgBoxStyle.Information)
End If
If d.Checked Then
MsgBox("The difference of the numbers " & num1 & " and " &
num2 & " is " & num2 - num1 & ".", MsgBoxStyle.Information)
End If
If m.Checked Then
MsgBox("The multiple of the numbers " & num1 & " and " &
num2 & " is " & num2 * num1 & ".", MsgBoxStyle.Information)
End If
If q.Checked Then
MsgBox("The quotient of the numbers " & num1 & " and " &
num2 & " is " & num2 / num1 & ".", MsgBoxStyle.Information)
End If
End If
If (s.Checked = False) And (d.Checked = False) And (m.Checked =
False) And (q.Checked = False) Then
MsgBox("No operation key has been selected. Please try again.", MsgBoxStyle.Exclamation, "Calculator")
End If
End Sub

'End of code
'*******************************
"Peter Proost" wrote:

when do you place the entered values in the double variables?

I propbably wont be able to reply anymore untill tomorrow

grtz peter

"Xero" <jeff@chezjeff(REMOVE).net> wrote in message
news:F9**********************************@microsof t.com...

Yes, it is.

"Peter Proost" wrote:

> is it a windows forms application?
>
> grtz Peter
>
>
> "Xero" <jeff@chezjeff(REMOVE).net> wrote in message
> news:D9**********************************@microsof t.com...
> > Sorry but they don't work either.
> > The code 'num1.Text' is underlined by a blue line, saying that 'Text

is

> not
> > a member of Double.'
> > Sorry that I forgot to tell you that both num1 and num2 are of

data type

> > 'Double'.
> >
> > "Peter Proost" wrote:
> >
> > > Here are 2 possible pieces of code, place it behind the click ev

ent of a

> > > button, or where you want to check the textboxes
> > >
> > > <<<<<<<code 1>>>>>>
> > >
> > > If Not IsNumeric(num1.Text) Or Not IsNumeric(num2.Text) Then
> > > MsgBox("one of the boxes is empty")
> > > End If
> > >
> > > <<<<<<code 1>>>>>>
> > >
> > > <<<<<<code 2>>>>>>
> > >
> > > Dim blnOk As Boolean
> > > If Not IsNumeric(num1.Text) Then
> > > blnOk = False
> > > MsgBox("Box one is empty")
> > > Else
> > > blnOk = True
> > > End If
> > > If Not IsNumeric(num2.Text) Then
> > > blnOk = False
> > > MsgBox("Box two is empty")
> > > Else
> > > blnOk = True
> > > End If
> > >
> > > If blnOk Then
> > > 'execute the rest of the code
> > > MsgBox("They're both filled")
> > > End If
> > >
> > > <<<<<<code 2>>>>>>>>
> > >
> > > greetz Peter
> > >
> > >
> > >
> > > "Xero" <jeff@chezjeff(REMOVE).net> wrote in message
> > > news:C0**********************************@microsof t.com...
> > > > Eh ... sorry, I still have some problem ...
> > > > I copied the line of code but it didn't work out.
> > > >
> > > > Could you post the exact line of code? I want to display the

message

> 'One
> > > of
> > > > the boxes is empty.' if any of the two boxes named as 'num1'

and > 'num2' is
> > > > left empty. Thanks again.
> > > >
> > > > "Peter Proost" wrote:
> > > >
> > > > > Hi,
> > > > >
> > > > > check if isnumeric(textbox.text)
> > > > > or for the length you could check textbox.text.length > 0
> > > > > or combine them
> > > > >
> > > > > hth
> > > > > Peter
> > > > > "Xero" <jeff@chezjeff(REMOVE).net> wrote in message
> > > > > news:F8**********************************@microsof t.com...
> > > > > > Hello. I am using Visual Studio .NET (Academic Edition) to

write a

> VB
> > > > > > program. My computer is running Win XP Pro.
> > > > > >
> > > > > > I am writing a calculator and requires users to enter two

numbers.

> > > After
> > > > > > entering the numbers, they should click a button called

'Display

> > > Results'.
> > > > > > How can I display a dialog box prompting the users to

check their

> > > entry if
> > > > > > they left any of the boxes empty? I have tried the .IsNaN

function

> but
> > > in
> > > > > > vein.
> > > > > >
> > > > > > Thanks.
> > > > > > --
> > > > > > Xero
> > > > > >
> > > > > > http://www.chezjeff.net
> > > > > > My personal web portal
> > > > >
> > > > >
> > > > >
> > >
> > >
> > >
>
>
>

[Xero]

It won't work either ...
An error box containing the following message appeared:
An unhandled exception of type 'System.InvalidCastException' occurred in
microsoft.visualbasic.dll

Additional information: Cast from string "" to type 'Double' is not valid.
"Peter Proost" wrote:

Hi, this code should do the trick

<<<<<<<<<<code>>>>>>>>>>>>

Dim num1 As Double
Dim num2 As Double
Dim blnOk As Boolean = True
If Not IsNumeric(TextBox1.Text) Then
blnOk = False
MsgBox("Box one is empty")
Else
num1 = TextBox1.Text
blnOk = True
End If
If Not IsNumeric(TextBox2.Text) Then
blnOk = False
MsgBox("Box two is empty")
Else
num2 = TextBox2.Text
blnOk = True
End If

If blnOk Then
If reverse.Checked = False Then
If s.Checked Then
MsgBox("The sum of the numbers " & num1 & " and " & num2
& " is " & num1 + num2 & ".", MsgBoxStyle.Information)
End If
If d.Checked Then
MsgBox("The difference of the numbers " & num1 & " and "
& num2 & " is " & num1 - num2 & ".", MsgBoxStyle.Information)
End If
If m.Checked Then
MsgBox("The multiple of the numbers " & num1 & " and " &
num2 & " is " & num1 * num2 & ".", MsgBoxStyle.Information)
End If
If q.Checked Then
MsgBox("The quotient of the numbers " & num1 & " and " &
num2 & " is " & num1 / num2 & ".", MsgBoxStyle.Information)
End If
End If
If reverse.Checked = True Then
If s.Checked Then
MsgBox("The sum of the numbers " & num1 & " and " & num2
& " is " & num2 + num1 & ".", MsgBoxStyle.Information)
End If
If d.Checked Then
MsgBox("The difference of the numbers " & num1 & " and "
& num2 & " is " & num2 - num1 & ".", MsgBoxStyle.Information)
End If
If m.Checked Then
MsgBox("The multiple of the numbers " & num1 & " and " &
num2 & " is " & num2 * num1 & ".", MsgBoxStyle.Information)
End If
If q.Checked Then
MsgBox("The quotient of the numbers " & num1 & " and " &
num2 & " is " & num2 / num1 & ".", MsgBoxStyle.Information)
End If
End If
If (s.Checked = False) And (d.Checked = False) And (m.Checked =
False) And (q.Checked = False) Then
MsgBox("No operation key has been selected. Please try
again.", MsgBoxStyle.Exclamation, "Calculator")
End If
End If

<<<<<<<<<code>>>>>>>>

greetz Peter
"Xero" <jeff@chezjeff(REMOVE).net> wrote in message
news:C3**********************************@microsof t.com...

Perhaps I should post the lines of code of the event handlier the 'Display
Result' button. Thanks again.

'*******************************
'Begin of code

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles Button1.Click
Dim num1 As Double
Dim num2 As Double
num1 = TextBox1.Text
num2 = TextBox2.Text
If reverse.Checked = False Then
If s.Checked Then
MsgBox("The sum of the numbers " & num1 & " and " & num2 &

"

is " & num1 + num2 & ".", MsgBoxStyle.Information)
End If
If d.Checked Then
MsgBox("The difference of the numbers " & num1 & " and " &
num2 & " is " & num1 - num2 & ".", MsgBoxStyle.Information)
End If
If m.Checked Then
MsgBox("The multiple of the numbers " & num1 & " and " &
num2 & " is " & num1 * num2 & ".", MsgBoxStyle.Information)
End If
If q.Checked Then
MsgBox("The quotient of the numbers " & num1 & " and " &
num2 & " is " & num1 / num2 & ".", MsgBoxStyle.Information)
End If
End If
If reverse.Checked = True Then
If s.Checked Then
MsgBox("The sum of the numbers " & num1 & " and " & num2 &

"

is " & num2 + num1 & ".", MsgBoxStyle.Information)
End If
If d.Checked Then
MsgBox("The difference of the numbers " & num1 & " and " &
num2 & " is " & num2 - num1 & ".", MsgBoxStyle.Information)
End If
If m.Checked Then
MsgBox("The multiple of the numbers " & num1 & " and " &
num2 & " is " & num2 * num1 & ".", MsgBoxStyle.Information)
End If
If q.Checked Then
MsgBox("The quotient of the numbers " & num1 & " and " &
num2 & " is " & num2 / num1 & ".", MsgBoxStyle.Information)
End If
End If
If (s.Checked = False) And (d.Checked = False) And (m.Checked =
False) And (q.Checked = False) Then
MsgBox("No operation key has been selected. Please try

again.",

MsgBoxStyle.Exclamation, "Calculator")
End If
End Sub

'End of code
'*******************************
"Peter Proost" wrote:

when do you place the entered values in the double variables?

I propbably wont be able to reply anymore untill tomorrow

grtz peter

"Xero" <jeff@chezjeff(REMOVE).net> wrote in message
news:F9**********************************@microsof t.com...
> Yes, it is.
>
> "Peter Proost" wrote:
>
> > is it a windows forms application?
> >
> > grtz Peter
> >
> >
> > "Xero" <jeff@chezjeff(REMOVE).net> wrote in message
> > news:D9**********************************@microsof t.com...
> > > Sorry but they don't work either.
> > > The code 'num1.Text' is underlined by a blue line, saying that 'Text is
> > not
> > > a member of Double.'
> > > Sorry that I forgot to tell you that both num1 and num2 are of data type
> > > 'Double'.
> > >
> > > "Peter Proost" wrote:
> > >
> > > > Here are 2 possible pieces of code, place it behind the click ev ent of a
> > > > button, or where you want to check the textboxes
> > > >
> > > > <<<<<<<code 1>>>>>>
> > > >
> > > > If Not IsNumeric(num1.Text) Or Not IsNumeric(num2.Text) Then
> > > > MsgBox("one of the boxes is empty")
> > > > End If
> > > >
> > > > <<<<<<code 1>>>>>>
> > > >
> > > > <<<<<<code 2>>>>>>
> > > >
> > > > Dim blnOk As Boolean
> > > > If Not IsNumeric(num1.Text) Then
> > > > blnOk = False
> > > > MsgBox("Box one is empty")
> > > > Else
> > > > blnOk = True
> > > > End If
> > > > If Not IsNumeric(num2.Text) Then
> > > > blnOk = False
> > > > MsgBox("Box two is empty")
> > > > Else
> > > > blnOk = True
> > > > End If
> > > >
> > > > If blnOk Then
> > > > 'execute the rest of the code
> > > > MsgBox("They're both filled")
> > > > End If
> > > >
> > > > <<<<<<code 2>>>>>>>>
> > > >
> > > > greetz Peter
> > > >
> > > >
> > > >
> > > > "Xero" <jeff@chezjeff(REMOVE).net> wrote in message
> > > > news:C0**********************************@microsof t.com...
> > > > > Eh ... sorry, I still have some problem ...
> > > > > I copied the line of code but it didn't work out.
> > > > >
> > > > > Could you post the exact line of code? I want to display the
message
> > 'One
> > > > of
> > > > > the boxes is empty.' if any of the two boxes named as 'num1' and > > 'num2' is
> > > > > left empty. Thanks again.
> > > > >
> > > > > "Peter Proost" wrote:
> > > > >
> > > > > > Hi,
> > > > > >
> > > > > > check if isnumeric(textbox.text)
> > > > > > or for the length you could check textbox.text.length > 0
> > > > > > or combine them
> > > > > >
> > > > > > hth
> > > > > > Peter
> > > > > > "Xero" <jeff@chezjeff(REMOVE).net> wrote in message
> > > > > > news:F8**********************************@microsof t.com...
> > > > > > > Hello. I am using Visual Studio .NET (Academic Edition) to
write a
> > VB
> > > > > > > program. My computer is running Win XP Pro.
> > > > > > >
> > > > > > > I am writing a calculator and requires users to enter two
numbers.
> > > > After
> > > > > > > entering the numbers, they should click a button called
'Display
> > > > Results'.
> > > > > > > How can I display a dialog box prompting the users to check their
> > > > entry if
> > > > > > > they left any of the boxes empty? I have tried the .IsNaN
function
> > but
> > > > in
> > > > > > > vein.
> > > > > > >
> > > > > > > Thanks.
> > > > > > > --
> > > > > > > Xero
> > > > > > >
> > > > > > > http://www.chezjeff.net
> > > > > > > My personal web portal
> > > > > >
> > > > > >
> > > > > >
> > > >
> > > >
> > > >
> >
> >
> >

[Peter Proost]

place num1 = cdbl(TextBox1.Text) and num2 = cdbl(TextBox2.Text) instead of
num1 = TextBox1.Text and num2 = TextBox2.Text, you probably have option
strict on that's what generates the error.

this piece of code I tested and works just fine:

<<<<<<code>>>>>>>
Dim num1 As Double
Dim num2 As Double
Dim blnOk As Boolean = True

If Not IsNumeric(TextBox1.Text) Then
blnOk = False
MsgBox("Box one is empty")
Else
num1 = CDbl(TextBox1.Text)
blnOk = True
End If

If Not IsNumeric(TextBox2.Text) Then
blnOk = False
MsgBox("Box two is empty")
Else
num2 = CDbl(TextBox2.Text)
blnOk = True
End If

<<<<<<code>>>>>>

greetz Peter

"Xero" <jeff@chezjeff(REMOVE).net> wrote in message
news:70**********************************@microsof t.com...

It won't work either ...
An error box containing the following message appeared:
An unhandled exception of type 'System.InvalidCastException' occurred in
microsoft.visualbasic.dll

Additional information: Cast from string "" to type 'Double' is not valid.
"Peter Proost" wrote:

Hi, this code should do the trick

<<<<<<<<<<code>>>>>>>>>>>>

Dim num1 As Double
Dim num2 As Double
Dim blnOk As Boolean = True
If Not IsNumeric(TextBox1.Text) Then
blnOk = False
MsgBox("Box one is empty")
Else
num1 = TextBox1.Text
blnOk = True
End If
If Not IsNumeric(TextBox2.Text) Then
blnOk = False
MsgBox("Box two is empty")
Else
num2 = TextBox2.Text
blnOk = True
End If

If blnOk Then
If reverse.Checked = False Then
If s.Checked Then
MsgBox("The sum of the numbers " & num1 & " and " & num2 & " is " & num1 + num2 & ".", MsgBoxStyle.Information)
End If
If d.Checked Then
MsgBox("The difference of the numbers " & num1 & " and " & num2 & " is " & num1 - num2 & ".", MsgBoxStyle.Information)
End If
If m.Checked Then
MsgBox("The multiple of the numbers " & num1 & " and " & num2 & " is " & num1 * num2 & ".", MsgBoxStyle.Information)
End If
If q.Checked Then
MsgBox("The quotient of the numbers " & num1 & " and " & num2 & " is " & num1 / num2 & ".", MsgBoxStyle.Information)
End If
End If
If reverse.Checked = True Then
If s.Checked Then
MsgBox("The sum of the numbers " & num1 & " and " & num2 & " is " & num2 + num1 & ".", MsgBoxStyle.Information)
End If
If d.Checked Then
MsgBox("The difference of the numbers " & num1 & " and " & num2 & " is " & num2 - num1 & ".", MsgBoxStyle.Information)
End If
If m.Checked Then
MsgBox("The multiple of the numbers " & num1 & " and " & num2 & " is " & num2 * num1 & ".", MsgBoxStyle.Information)
End If
If q.Checked Then
MsgBox("The quotient of the numbers " & num1 & " and " & num2 & " is " & num2 / num1 & ".", MsgBoxStyle.Information)
End If
End If
If (s.Checked = False) And (d.Checked = False) And (m.Checked = False) And (q.Checked = False) Then
MsgBox("No operation key has been selected. Please try
again.", MsgBoxStyle.Exclamation, "Calculator")
End If
End If

<<<<<<<<<code>>>>>>>>

greetz Peter
"Xero" <jeff@chezjeff(REMOVE).net> wrote in message
news:C3**********************************@microsof t.com...

Perhaps I should post the lines of code of the event handlier the 'Display Result' button. Thanks again.

'*******************************
'Begin of code

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim num1 As Double
Dim num2 As Double
num1 = TextBox1.Text
num2 = TextBox2.Text
If reverse.Checked = False Then
If s.Checked Then
MsgBox("The sum of the numbers " & num1 & " and " & num2 &

"

is " & num1 + num2 & ".", MsgBoxStyle.Information)
End If
If d.Checked Then
MsgBox("The difference of the numbers " & num1 & " and

" & num2 & " is " & num1 - num2 & ".", MsgBoxStyle.Information)
End If
If m.Checked Then
MsgBox("The multiple of the numbers " & num1 & " and " & num2 & " is " & num1 * num2 & ".", MsgBoxStyle.Information)
End If
If q.Checked Then
MsgBox("The quotient of the numbers " & num1 & " and " & num2 & " is " & num1 / num2 & ".", MsgBoxStyle.Information)
End If
End If
If reverse.Checked = True Then
If s.Checked Then
MsgBox("The sum of the numbers " & num1 & " and " & num2 & "

is " & num2 + num1 & ".", MsgBoxStyle.Information)
End If
If d.Checked Then
MsgBox("The difference of the numbers " & num1 & " and

" & num2 & " is " & num2 - num1 & ".", MsgBoxStyle.Information)
End If
If m.Checked Then
MsgBox("The multiple of the numbers " & num1 & " and " & num2 & " is " & num2 * num1 & ".", MsgBoxStyle.Information)
End If
If q.Checked Then
MsgBox("The quotient of the numbers " & num1 & " and " & num2 & " is " & num2 / num1 & ".", MsgBoxStyle.Information)
End If
End If
If (s.Checked = False) And (d.Checked = False) And (m.Checked = False) And (q.Checked = False) Then
MsgBox("No operation key has been selected. Please try

again.",

MsgBoxStyle.Exclamation, "Calculator")
End If
End Sub

'End of code
'*******************************
"Peter Proost" wrote:

> when do you place the entered values in the double variables?
>
> I propbably wont be able to reply anymore untill tomorrow
>
> grtz peter
>
> "Xero" <jeff@chezjeff(REMOVE).net> wrote in message
> news:F9**********************************@microsof t.com...
> > Yes, it is.
> >
> > "Peter Proost" wrote:
> >
> > > is it a windows forms application?
> > >
> > > grtz Peter
> > >
> > >
> > > "Xero" <jeff@chezjeff(REMOVE).net> wrote in message
> > > news:D9**********************************@microsof t.com...
> > > > Sorry but they don't work either.
> > > > The code 'num1.Text' is underlined by a blue line, saying that

'Text

> is
> > > not
> > > > a member of Double.'
> > > > Sorry that I forgot to tell you that both num1 and num2 are of

data

> type
> > > > 'Double'.
> > > >
> > > > "Peter Proost" wrote:
> > > >
> > > > > Here are 2 possible pieces of code, place it behind the click ev ent

> of a
> > > > > button, or where you want to check the textboxes
> > > > >
> > > > > <<<<<<<code 1>>>>>>
> > > > >
> > > > > If Not IsNumeric(num1.Text) Or Not IsNumeric(num2.Text) Then
> > > > > MsgBox("one of the boxes is empty")
> > > > > End If
> > > > >
> > > > > <<<<<<code 1>>>>>>
> > > > >
> > > > > <<<<<<code 2>>>>>>
> > > > >
> > > > > Dim blnOk As Boolean
> > > > > If Not IsNumeric(num1.Text) Then
> > > > > blnOk = False
> > > > > MsgBox("Box one is empty")
> > > > > Else
> > > > > blnOk = True
> > > > > End If
> > > > > If Not IsNumeric(num2.Text) Then
> > > > > blnOk = False
> > > > > MsgBox("Box two is empty")
> > > > > Else
> > > > > blnOk = True
> > > > > End If
> > > > >
> > > > > If blnOk Then
> > > > > 'execute the rest of the code
> > > > > MsgBox("They're both filled")
> > > > > End If
> > > > >
> > > > > <<<<<<code 2>>>>>>>>
> > > > >
> > > > > greetz Peter
> > > > >
> > > > >
> > > > >
> > > > > "Xero" <jeff@chezjeff(REMOVE).net> wrote in message
> > > > > news:C0**********************************@microsof t.com...
> > > > > > Eh ... sorry, I still have some problem ...
> > > > > > I copied the line of code but it didn't work out.
> > > > > >
> > > > > > Could you post the exact line of code? I want to display

the > message
> > > 'One
> > > > > of
> > > > > > the boxes is empty.' if any of the two boxes named as 'num1' and

> > > 'num2' is
> > > > > > left empty. Thanks again.
> > > > > >
> > > > > > "Peter Proost" wrote:
> > > > > >
> > > > > > > Hi,
> > > > > > >
> > > > > > > check if isnumeric(textbox.text)
> > > > > > > or for the length you could check textbox.text.length >

0 > > > > > > > or combine them
> > > > > > >
> > > > > > > hth
> > > > > > > Peter
> > > > > > > "Xero" <jeff@chezjeff(REMOVE).net> wrote in message
> > > > > > > news:F8**********************************@microsof t.com... > > > > > > > > Hello. I am using Visual Studio .NET (Academic Edition) to > write a
> > > VB
> > > > > > > > program. My computer is running Win XP Pro.
> > > > > > > >
> > > > > > > > I am writing a calculator and requires users to enter two > numbers.
> > > > > After
> > > > > > > > entering the numbers, they should click a button called > 'Display
> > > > > Results'.
> > > > > > > > How can I display a dialog box prompting the users to

check

> their
> > > > > entry if
> > > > > > > > they left any of the boxes empty? I have tried the ..IsNaN > function
> > > but
> > > > > in
> > > > > > > > vein.
> > > > > > > >
> > > > > > > > Thanks.
> > > > > > > > --
> > > > > > > > Xero
> > > > > > > >
> > > > > > > > http://www.chezjeff.net
> > > > > > > > My personal web portal
> > > > > > >
> > > > > > >
> > > > > > >
> > > > >
> > > > >
> > > > >
> > >
> > >
> > >
>
>
>

[Xero]

Hi. The code does the trick. Thanks very very much.

Xero
"Peter Proost" wrote:

place num1 = cdbl(TextBox1.Text) and num2 = cdbl(TextBox2.Text) instead of
num1 = TextBox1.Text and num2 = TextBox2.Text, you probably have option
strict on that's what generates the error.

this piece of code I tested and works just fine:

<<<<<<code>>>>>>>
Dim num1 As Double
Dim num2 As Double
Dim blnOk As Boolean = True

If Not IsNumeric(TextBox1.Text) Then
blnOk = False
MsgBox("Box one is empty")
Else
num1 = CDbl(TextBox1.Text)
blnOk = True
End If

If Not IsNumeric(TextBox2.Text) Then
blnOk = False
MsgBox("Box two is empty")
Else
num2 = CDbl(TextBox2.Text)
blnOk = True
End If

<<<<<<code>>>>>>

greetz Peter

"Xero" <jeff@chezjeff(REMOVE).net> wrote in message
news:70**********************************@microsof t.com...

It won't work either ...
An error box containing the following message appeared:
An unhandled exception of type 'System.InvalidCastException' occurred in
microsoft.visualbasic.dll

Additional information: Cast from string "" to type 'Double' is not valid.
"Peter Proost" wrote:

Hi, this code should do the trick

<<<<<<<<<<code>>>>>>>>>>>>

Dim num1 As Double
Dim num2 As Double
Dim blnOk As Boolean = True
If Not IsNumeric(TextBox1.Text) Then
blnOk = False
MsgBox("Box one is empty")
Else
num1 = TextBox1.Text
blnOk = True
End If
If Not IsNumeric(TextBox2.Text) Then
blnOk = False
MsgBox("Box two is empty")
Else
num2 = TextBox2.Text
blnOk = True
End If

If blnOk Then
If reverse.Checked = False Then
If s.Checked Then
MsgBox("The sum of the numbers " & num1 & " and " & num2 & " is " & num1 + num2 & ".", MsgBoxStyle.Information)
End If
If d.Checked Then
MsgBox("The difference of the numbers " & num1 & " and " & num2 & " is " & num1 - num2 & ".", MsgBoxStyle.Information)
End If
If m.Checked Then
MsgBox("The multiple of the numbers " & num1 & " and " & num2 & " is " & num1 * num2 & ".", MsgBoxStyle.Information)
End If
If q.Checked Then
MsgBox("The quotient of the numbers " & num1 & " and " & num2 & " is " & num1 / num2 & ".", MsgBoxStyle.Information)
End If
End If
If reverse.Checked = True Then
If s.Checked Then
MsgBox("The sum of the numbers " & num1 & " and " & num2 & " is " & num2 + num1 & ".", MsgBoxStyle.Information)
End If
If d.Checked Then
MsgBox("The difference of the numbers " & num1 & " and " & num2 & " is " & num2 - num1 & ".", MsgBoxStyle.Information)
End If
If m.Checked Then
MsgBox("The multiple of the numbers " & num1 & " and " & num2 & " is " & num2 * num1 & ".", MsgBoxStyle.Information)
End If
If q.Checked Then
MsgBox("The quotient of the numbers " & num1 & " and " & num2 & " is " & num2 / num1 & ".", MsgBoxStyle.Information)
End If
End If
If (s.Checked = False) And (d.Checked = False) And (m.Checked = False) And (q.Checked = False) Then
MsgBox("No operation key has been selected. Please try
again.", MsgBoxStyle.Exclamation, "Calculator")
End If
End If

<<<<<<<<<code>>>>>>>>

greetz Peter
"Xero" <jeff@chezjeff(REMOVE).net> wrote in message
news:C3**********************************@microsof t.com...
> Perhaps I should post the lines of code of the event handlier the 'Display > Result' button. Thanks again.
>
> '*******************************
> 'Begin of code
>
> Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As > System.EventArgs) Handles Button1.Click
> Dim num1 As Double
> Dim num2 As Double
> num1 = TextBox1.Text
> num2 = TextBox2.Text
> If reverse.Checked = False Then
> If s.Checked Then
> MsgBox("The sum of the numbers " & num1 & " and " & num2 & "
> is " & num1 + num2 & ".", MsgBoxStyle.Information)
> End If
> If d.Checked Then
> MsgBox("The difference of the numbers " & num1 & " and " & > num2 & " is " & num1 - num2 & ".", MsgBoxStyle.Information)
> End If
> If m.Checked Then
> MsgBox("The multiple of the numbers " & num1 & " and " & > num2 & " is " & num1 * num2 & ".", MsgBoxStyle.Information)
> End If
> If q.Checked Then
> MsgBox("The quotient of the numbers " & num1 & " and " & > num2 & " is " & num1 / num2 & ".", MsgBoxStyle.Information)
> End If
> End If
> If reverse.Checked = True Then
> If s.Checked Then
> MsgBox("The sum of the numbers " & num1 & " and " & num2 & "
> is " & num2 + num1 & ".", MsgBoxStyle.Information)
> End If
> If d.Checked Then
> MsgBox("The difference of the numbers " & num1 & " and " & > num2 & " is " & num2 - num1 & ".", MsgBoxStyle.Information)
> End If
> If m.Checked Then
> MsgBox("The multiple of the numbers " & num1 & " and " & > num2 & " is " & num2 * num1 & ".", MsgBoxStyle.Information)
> End If
> If q.Checked Then
> MsgBox("The quotient of the numbers " & num1 & " and " & > num2 & " is " & num2 / num1 & ".", MsgBoxStyle.Information)
> End If
> End If
> If (s.Checked = False) And (d.Checked = False) And (m.Checked = > False) And (q.Checked = False) Then
> MsgBox("No operation key has been selected. Please try
again.",
> MsgBoxStyle.Exclamation, "Calculator")
> End If
> End Sub
>
> 'End of code
> '*******************************
>
>
> "Peter Proost" wrote:
>
> > when do you place the entered values in the double variables?
> >
> > I propbably wont be able to reply anymore untill tomorrow
> >
> > grtz peter
> >
> > "Xero" <jeff@chezjeff(REMOVE).net> wrote in message
> > news:F9**********************************@microsof t.com...
> > > Yes, it is.
> > >
> > > "Peter Proost" wrote:
> > >
> > > > is it a windows forms application?
> > > >
> > > > grtz Peter
> > > >
> > > >
> > > > "Xero" <jeff@chezjeff(REMOVE).net> wrote in message
> > > > news:D9**********************************@microsof t.com...
> > > > > Sorry but they don't work either.
> > > > > The code 'num1.Text' is underlined by a blue line, saying that
'Text
> > is
> > > > not
> > > > > a member of Double.'
> > > > > Sorry that I forgot to tell you that both num1 and num2 are of
data
> > type
> > > > > 'Double'.
> > > > >
> > > > > "Peter Proost" wrote:
> > > > >
> > > > > > Here are 2 possible pieces of code, place it behind the click ev ent
> > of a
> > > > > > button, or where you want to check the textboxes
> > > > > >
> > > > > > <<<<<<<code 1>>>>>>
> > > > > >
> > > > > > If Not IsNumeric(num1.Text) Or Not IsNumeric(num2.Text) Then
> > > > > > MsgBox("one of the boxes is empty")
> > > > > > End If
> > > > > >
> > > > > > <<<<<<code 1>>>>>>
> > > > > >
> > > > > > <<<<<<code 2>>>>>>
> > > > > >
> > > > > > Dim blnOk As Boolean
> > > > > > If Not IsNumeric(num1.Text) Then
> > > > > > blnOk = False
> > > > > > MsgBox("Box one is empty")
> > > > > > Else
> > > > > > blnOk = True
> > > > > > End If
> > > > > > If Not IsNumeric(num2.Text) Then
> > > > > > blnOk = False
> > > > > > MsgBox("Box two is empty")
> > > > > > Else
> > > > > > blnOk = True
> > > > > > End If
> > > > > >
> > > > > > If blnOk Then
> > > > > > 'execute the rest of the code
> > > > > > MsgBox("They're both filled")
> > > > > > End If
> > > > > >
> > > > > > <<<<<<code 2>>>>>>>>
> > > > > >
> > > > > > greetz Peter
> > > > > >
> > > > > >
> > > > > >
> > > > > > "Xero" <jeff@chezjeff(REMOVE).net> wrote in message
> > > > > > news:C0**********************************@microsof t.com...
> > > > > > > Eh ... sorry, I still have some problem ...
> > > > > > > I copied the line of code but it didn't work out.
> > > > > > >
> > > > > > > Could you post the exact line of code? I want to display the > > message
> > > > 'One
> > > > > > of
> > > > > > > the boxes is empty.' if any of the two boxes named as 'num1' and
> > > > 'num2' is
> > > > > > > left empty. Thanks again.
> > > > > > >
> > > > > > > "Peter Proost" wrote:
> > > > > > >
> > > > > > > > Hi,
> > > > > > > >
> > > > > > > > check if isnumeric(textbox.text)
> > > > > > > > or for the length you could check textbox.text.length > 0 > > > > > > > > or combine them
> > > > > > > >
> > > > > > > > hth
> > > > > > > > Peter
> > > > > > > > "Xero" <jeff@chezjeff(REMOVE).net> wrote in message
> > > > > > > > news:F8**********************************@microsof t.com... > > > > > > > > > Hello. I am using Visual Studio .NET (Academic Edition) to > > write a
> > > > VB
> > > > > > > > > program. My computer is running Win XP Pro.
> > > > > > > > >
> > > > > > > > > I am writing a calculator and requires users to enter two > > numbers.
> > > > > > After
> > > > > > > > > entering the numbers, they should click a button called > > 'Display
> > > > > > Results'.
> > > > > > > > > How can I display a dialog box prompting the users to
check
> > their
> > > > > > entry if
> > > > > > > > > they left any of the boxes empty? I have tried the ..IsNaN > > function
> > > > but
> > > > > > in
> > > > > > > > > vein.
> > > > > > > > >
> > > > > > > > > Thanks.
> > > > > > > > > --
> > > > > > > > > Xero
> > > > > > > > >
> > > > > > > > > http://www.chezjeff.net
> > > > > > > > > My personal web portal
> > > > > > > >
> > > > > > > >
> > > > > > > >
> > > > > >
> > > > > >
> > > > > >
> > > >
> > > >
> > > >
> >
> >
> >