Require text input in a field dependant on toggle button

[thekruser]

What I have:


tblPersonal
-tgbNotAvailable
-txtNotAvailableReason

What I am trying to do:
I would like for txtNotAvailableReason to be required when a clerk activates tgbNotAvailable. I can instruct clerks I have now to do it, but I need to make sure they do.

The problem:
I have absolutely no idea where to even begin with this, let alone how to make it happen.

Thank you in advance for your time and help.

[pbaldy]

Not sure if there's a validation rule to handle the conditional nature of the data. I'd use the before update event of the form:

http://www.baldyweb.com/BeforeUpdate.htm

Your test would be along the lines of:

If Me.tgbNotAvailable = Whatever AND Len(Me.txtNotAvailableReason & vbNullString) = 0 Then