Is this code right?

This code is not working and im not sure why?

on (press) {_root.on_mc.gotoAndStop(3);

}
on (rollOver) {_root.on_mc.gotoAndStop(2);

}
on (rollOut) {_root.on_mc.gotoAndStop(1);

}
on (release) {_root.lightblub_mc.gotoAndStop("on"); 

} 

Thanx for any help
Ben