I am new to the VBA world. I have a form that I am trying to validate the fields on. They are either text boxes or combo boxes. I have a custom function that is called when the user clicks a command button. I cannot test any of these fields for no user input or null. None of these work:

If (Me.txtProductCode = Null) Then
  ' some code here
End if

or

If Len (Me.txtProductCode) = Null Then
  ' some code here
End if
or

If Len(Me.txtProductCode) = 0 Then
  ' some code here
End if

If IsNull(Me.txtProductCode) = True Then
  ' some code here
End if

I have tried to use the expression builder but it is very confusing for me. I'd rather do this in VB code. So, how do you check the contents of form fields in VB? Where is there some very good examples of this? Thanks

[email protected]

Try following :

If Len(Me.txtProductCode) > 0 Then
  ' some code here
End if

Regards,
Ashfaque

I generally use the simple form:

If IsNull(Me.txtProductCode) Or Me.txtProductCode = "" Then
  ' some code here
End if

You can't test for null After you take a control value, so (Me.txtProductCode) = Null won't work (in Jet.) You have to tell Jet you are going to check for a Null value first IsNull() or else Jet will throw a fit when it hits the = sign, because Null values are not equal to anything.

Optionally, you can enforce this sort of issue at the table design level if the form is based on a table by making the fields required, and having some validation rule there, rather than in the form.

HTH

mmcdonal