Actionscript error :( : im just a beginner at this and i would really appreciate some help :)
This is my code:

    import flash.events.MouseEvent;
    import flash.display.MovieClip;
    
    var currentButton:MovieClip
    button1.addEventListener(MouseEvent.CLICK, mouseClick);
    button2.addEventListener(MouseEvent.CLICK, mouseClick);
    button3.addEventListener(MouseEvent.CLICK, mouseClick);
    button4.addEventListener(MouseEvent.CLICK, mouseClick);
    function mouseClick(event:MouseEvent):void {
    	currentButton.alpha = 1;
    	currentButton.mouseEnabled = true;
    	currentButton = event.target as MovieClip;
    	trace("CLICK");
    	currentButton.alpha = 0.7;
    	currentButton.mouseEnabled = false;
    }

But i get this error when i click on a button:
TypeError: Error #1009: Cannot access a property or method of a null object reference.
	at Untitled_fla::MainTimeline/mouseClick()
sorry if i didnt post this question right, im just new here
