check box to determine whether sales tax applied

[Hughesb6]

I have a form that has field called "Charge",an unbound check box called "Check127", and a field called "Tax Amount". If the check box is checked I want the field "Charge" to be multiplied by .06 and the result to be in the field "Tax Amount". If the box is not checked I want "0" to be in the "Tax Amount" field.

[twinnyfo]

Hughesb6,

Welcome to Bytes!

You would set the ControlSource for the "Tax Amount" Text box to:

=IIf([Check127], [Charge] * 0.06, 0)

Hope that hepps!

[Hughesb6]

That didn't work, I still get the error.

[PhilOfWalton]

I think Twinnyfo meant the ControlSource, not the RecordSource.

What he has posted is perfectly correct, but I think

=IIf([Check127] = True, [Charge] * 0.06, 0)

is clearer to understand.

Phil

[twinnyfo]

Yes - thanks for the catch, Phil. ControlSource--not RecordSource.

[Hughesb6]

That worked, I had a misspell. Thank you both for your help!!

[twinnyfo]

Glad we could hepp! Phil caught my glitch, though!

[NeoPa]

HughesB6:
That didn't work, I still get the error.

What error? You mentioned no error.

When asking for help it's better that, when you have an error then please state the problem as clearly as you can. If there is an error showing then, obviously, include the full text of that error.

In this case it's clear that we've passed that stage, but I'm hoping you'll continue to benefit from Bytes.com with new questions.

As far as comparing boolean values to True or False is concerned, this topic's been covered in detail before. It's not a good idea as it encourages developers to think like non-developers (Not a flattering comparison). Furthermore, it can lead to very hard to figure out logic errors, as not everything that can be used as a boolean necessarily has acceptable boolean values. So, if you absolutely must compare to one or other, then always compare to False. That way you'll never actually introduce any logic inaccuracies.