I would like to do data validation in the BeforeUpdate procedure, but Access gives me a runtime error when I try to do this:



An example of what I am trying to do is as follows:

Code:
Private Sub Option_BeforeUpdate(Cancel As Integer)
  If Option = A Then
    Answer=MsgBox("Don't you mean B?",vbYesNo)
    If Answer = vbYes Then
      Cancel = True
      Option = B
...