Removing enterframe events

programming flash
1

Hi Note my code below


this.addEventListener(Event.ENTER_FRAME,follow);
function follow(evt:Event):void {
	addChild(mouseThing_mc);
	var xMouse:Number=(stage.mouseX);
	var yMouse:Number=(stage.mouseY);
	var xH:Number=mouseThing_mc.x;
	var yH:Number=mouseThing_mc.y;

	mouseThing_mc.x=xMouse;
	mouseThing_mc.y=yMouse;

}
// SOME OTHER STUFF HAPPENS IN HERE AND FINALLY

var menuItem11:ContextMenuItem=new ContextMenuItem("Home");
menuItem11.addEventListener(ContextMenuEvent.MENU_ITEM_SELECT, home1);

function home1(event:ContextMenuEvent):void {
	this.removeEventListener(Event.ENTER_FRAME,follow);
	MovieClip(root).gotoAndPlay("out_point2");
}

So when I navigate out of this movieclip once the function home1 is fired, I get the following error

TypeError: Error #1009: Cannot access a property or method of a null object reference.
at home_fla::mc_content_13/follow()

I know it is the function looking for that mouseThing_mc that is not there. Any ideas?