There's probably a simple answer to this, but reading all about RETURN .F., DODEFAULT() and NODEFAULT, and experimenting with all kinds of code hasn't resulted in a simple solution. I'm trying to validate a checkbox when the user checks the box and appropriately check or not check the box, and it just doesn't seem to want to cooperate.

If I put "RETURN .F." in the WHEN() of the checkbox, it works fine in that it doesn't check the box when I click it. Obviously, that isn't very useful by itself. But when I add my conditional statement, it no longer works for some reason. It seems like something like this in the WHEN() of the checkbox would work, but it doesn't.

IF 7=MessageBox("Are you sure want to select " + gcSelection + "?",48+4) && or whatever criteria
   Return .F.
ENDIF

How do I accomplish this in a simple way?

Thanks.