I've always wondered why elevators don't have a "cancel" button. Many, many times, I've have pressed the wrong floor button forcing me to stop and then continue to the right floor. Not mention the smart ass kid that presses every button just before I enter the elevator ;)
If they offered a 'cancel' button, the kid can also hit the 'cancel' button on his way out and destroy all the other floor choices people already picked.
I've seen elevators where if you quickly press a button couple of times, the button will turn off (if it were already on). This of course doesn't protect you from the mischievous kid who presses every button possible.
That's easy to fix, though, they just press their floor number again. If all the buttons are pressed there is nothing they can do (unless they know the secret reset password).
