>>I think your approach should work, but I want to ask a question: Why do we need to put a code into valid event of button (Add button). For me it seems no sense.
>
>I read the question a little fast, and saw "cannot move focus in valid event" and assumed what the rest of the questoin was. I didn't answer it very well, so just ignore that

Your approach would work pretty well with textboxes (as obvious example), which require validation.