Sure, I understand that the command button is not relevant when the checkbox
is not ticked. But my point is this: making a command button visible &
invisible is a non-standard way of dealing with that situation. Users tend
to think, "Oh, what's wrong, that command button just disappeared!" The
standard way to do it, is to make the button disabled when it is not
relevant. If you look at other programs, you'll find that the vast majoruty
use disabling - not invisibling (!) - in these situations.
But of course, either will work, in terms of achieving the desired end
result!
Cheers,
TC