stage.addEventListener(KeyboardEvent.KEY_DOWN, hiddenKeysDown_handler);
stage.addEventListener(KeyboardEvent.KEY_UP, hiddenKeysUp_handler);

//Key Handlers
private function hiddenKeysDown_handler(e:KeyboardEvent):void{
	if (e.ctrlKey && e.shiftKey && e.altKey) {		
			// do something
	}			
}

private function hiddenKeysUp_handler(e:KeyboardEvent):void{
	//stop doing something	
}

stage.addEventListener(KeyboardEvent.KEY_DOWN, hiddenKeysDown_handler);
stage.addEventListener(KeyboardEvent.KEY_UP, hiddenKeysUp_handler);

//Key Handlers
                                private function hiddenKeysDown_handler(e:KeyboardEvent):void
                                {
                                                if (e.ctrlKey && e.shiftKey && e.altKey) 
                                                {
                                                                
                                                                for (var i:int = 0; i < HotSpotSets.length; i++) 
                                                                {
                                                                                for (var j:int = 0; j < HotSpotSets[i].length; j++) 
                                                                                {
                                                                                                
                                                                                                HotSpotSets[i][j].showHotSpots(true);
                                                                                                
                                                                                }
                                                                }
                                                }
                                                
                                }
                                
                                private function hiddenKeysUp_handler(e:KeyboardEvent):void
                                {
                                                for (var i:int = 0; i < HotSpotSets.length; i++) 
                                                {
                                                                for (var j:int = 0; j < HotSpotSets[i].length; j++) 
                                                                {
                                                                                
                                                                                HotSpotSets[i][j].showHotSpots(false);
                                                                                
                                                                }
                                                }
                                                
                                }

Key Handlers

Key handlers for ctrl alt combos

Key handlers (ctrl alt combos)

ActionScript 3