I'd click it and it won't do anything , I know it should turn off when I'm at a stoplight to save gas!
Put more pressure on brake pedal when the car at stationary and it should kill the engine....The motor will not stop with light pressure on brake pedal.

I press the button for autostart stop, it won't do anything.
The button is to switch ON/OFF this feature only, not to stop/start the engine.