Hey Guys, I need to know when the client enters fullscreen mode and can't figure it out. I've tried to create an alert when self fullscreen equals yes but can't get the alert to work.

SCRIPT
Code:
function dog(){
if(self.fullscreen=='yes'){//is this possible
alert('You are in Full Screen Mode')
}}

addEvent(window,'load',function(){dog();},false);
Thanks in advance