>>You can hide the button behind some other control or mark it Visible = .f. if you don't want users to see it.
>
>If the button is invisible, the Esc won't work. You can move it off to the side though.

I should have tested it. I've called click() on invisible buttons often enough, I assumed ESC could be handled the same way. As you say, though, it's easy to hide a button.