I dont know exactly, what is the name of this button.
But i think about the only button in the bottom part of the device (iPad, Ihpone) (the round button with the square ))) )
And in your answer, i see that it is impossible?
Really? do not just intercept the request when you click on this button?
I want that in the running application, when you click on this button, user (children) didn't leave app, and app asked for the password. Or simply not given a set time to leave this application. (i hope, i didn't make a lot of mistakes ))) )