Remove instance of movieclip with click?

1

Hi

I am using a loop to add 10 shapes to the stage, then i just want to click on one at a time, in any random order and make it alpha 0, im using this code… it gets rid of some shapes but not all. i dont get it?

var shape:MovieClip;


for (var i:Number = 0; i < 10; i++)
	{
	shape = new ShapeW();
	var randomX:Number = Math.random() * 550;
	addChild(shape);
	shape.rotation = i*4;
	shape.x = randomX;
	shape.y = randomX;
	shape.addEventListener(MouseEvent.CLICK, changeColour);
	}


function changeColour(e:MouseEvent):void
{
	
	e.target.alpha = 0;
}

any help would be sweet!