If Statement To Check If IsNull field

[data808]

I have something I haven't come across before or at least I haven't noticed. I may have to check all my other forms now. Anyway, I have this coded behind a save button:

If Me.Dirty Then    
    If IsNull(Me.txtReason) Then
        MsgBox "Please Enter A Reason.", vbInformation, "Requirement"
        Me.txtReason.SetFocus
        Exit Sub
    End If
        If MsgBox("Save Changes?", vbYesNo, "Save") = vbYes Then            
            DoCmd.RunCommand acCmdSaveRecord
            Me.cmbCustomer.SetFocus
            Exit Sub
        Else
            Me.cmbCustomer.SetFocus
            Exit Sub
        End If
End if

So it works fine sometimes. If I don't type anything into the txtReason field and click the save button it will execute as it should and prompt me to make sure to type something into the txtReason field. But if I type into the txtReason field and then backspace but leave the focus on that field, meaning the cursor doesn't leave that field, it will still allow me to save the record even though the txtReason field is blank.

Does anyone know how to fix this?

[data808]

Also found out that this behavior is immune to combo boxes. If I mess with the combo box by saving it with or without text it will always prompt me select one of the values from the drop down list if I leave the combo box blank.

[data808]

Ok I figured out the problem. I also need to add "" to the code. So it should look like this:

If Me.Dirty Then        
    If IsNull(Me.txtReason) Or Me.txtReason.Value = "" Then
        MsgBox "Please Enter A Reason.", vbInformation, "Requirement"
        Me.txtReason.SetFocus
        Exit Sub
    End If
        If MsgBox("Save Changes?", vbYesNo, "Save") = vbYes Then            
            DoCmd.RunCommand acCmdSaveRecord
            Me.cmbCustomer.SetFocus
            Exit Sub
        Else
            Me.cmbCustomer.SetFocus
            Exit Sub
        End If 
End if

[Micron]

IIRC, it is often done as
If Me.txtReason & vbNullString = "" Then

That way, if the control is null you're concatenating "" and asking if it contains "", so True. If it's not null then "Because I'm lazy" & vbNullString = "Because I'm lazy" then not True. Careful with that though, because if you concatenate vbNullString on to a numeric value, the value becomes a string.