Filips Benoit wrote:
Hi,
TBL_CONTACT_PERSON
CNTP_ID (auto)
CNTP_LAST_NAME (required = yes)
CNTP_FUNCTION (required = no)
CNTP_..... (all required = no)
FRM_CONTACT_PERSON_ADD_NEW
Property DATA ENTRY = YES
No closebutton ( user leaves pressing 'Add' or 'Exit no adding'
CmdAdd
CmdExitNoAdd
Problem with Private Sub CmdAdd_Click() > see code below *********
If the user presses 'add' i want to test if Me.CNTP_LAST_NAME has data. If
not > MsgBox "Unable to add person without LastName!" and stay in the form.
1. if i do not enter any value in any field the test
IsNull(Me.CNTP_LAST_NAME) returns True
but MsgBox Me.CNTP_LAST_NAME triggers error 'invalid use of null" ???
2. if i only enter the CNTP_FUNCTION leaving Me.CNTP_LAST_NAME blanc, the
test IsNull(Me.CNTP_LAST_NAME) returns False
Please help,
Filip
************************************************** **************************
**********
Private Sub CmdAdd_Click()
On Error GoTo ErrHandling
If IsNull(Me.CNTP_LAST_NAME) Then
MsgBox Me.CNTP_LAST_NAME 'this msgbox is just for testing
MsgBox "Unable to add person, need LastName!"
Exit Sub
Else
DoCmd.Close acForm, Me.Name, acSaveYes
End If
Exit Sub
ErrHandling:
MsgBox Err.Number & " " & Err.Description
End Sub
************************************************** **
Yes, the MsgBox function requires a string expression as the prompt,
hence the error when you send null to it.
Why Me.CNTP_LAST_NAME would not yield a null if left blank is a bit of a
mystery, but one thing I'd suggest is to use the notation
Me!CNTP_LAST_NAME or Me("CNTP_LAST_NAME") as matter of course as the dot
should be for properties and methods, not memebers of collections. This
may not be the cause of the problem here but may cause problems elsewhere.
Set a breakpoint where your test fails and use the imeediate window to
test the field's value, e.g.
?CNTP_LAST_NAME
?Isnull(CNTP_LAST_NAME)
?Len(CNTP_LAST_NAME)
?CNTP_LAST_NAME=""
See what transpires, there may be some other code or something else
setting the field to a zero length string, which isn't null but you
can't tell the difference by looking at it on the screen, both null and
zero length string will look just blank.
