import flash.display.StageDisplayState;
   import mx.managers.SystemManager;
  
  public function toggle():void {
    try {
    switch (systemManager.stage.displayState) {
     case StageDisplayState.FULL_SCREEN:
       systemManager.stage.displayState =
             StageDisplayState.NORMAL;
       break;
     default: systemManager.stage.displayState =
           StageDisplayState.FULL_SCREEN;
     break;
     }
    } catch (err:SecurityError) {
              // ignore
     }
   }
  
    
   
  ]]>
  </mx:Script>