Whether the OP, who hasn't come back, knew they were starting a flame war by asking this question...
There is no context-less "right place" to place validation logic, nor are the various options mutually exclusive.
David J.
This I can wholeheartedly agree with. And my apologies if I came across as "flaming". Not my intention at all. I'm simply here to learn (and, well, offer my opinion from time to time :) )