// write as3 code here.. package { import flash.display.Sprite; import flash.display.Stage; import flash.events.MouseEvent; public class Test extends Sprite { public function Test() { var btn :Sprite = new Sprite; addChild( btn ); btn.graphics.beginFill(0xFF0000); btn.graphics.drawRect(0,0,100,100); btn.buttonMode = true; btn.addEventListener( MouseEvent.CLICK, onclick ); } private function onclick( e :MouseEvent ) :void { switch(stage.displayState) { case "normal": stage.displayState = "fullScreen"; break; case "fullScreen": default: stage.displayState = "normal"; break; } } } }