Why is this NULL?

programming flash
1

When I run this snippet of code, I am getting “TypeError: Error #1009: Cannot access a property or method of a null object reference.
at mouseMoveSlider02_fla::MainTimeline/init()
at mouseMoveSlider02_fla::MainTimeline/frame1()”

Please help if you could. Many thanks.


var guideBoxes:Array = [];

function init(e:Event = null):void
{
    removeEventListener(Event.ADDED_TO_STAGE, init);

    var nextXPos:Number;
    var mc:MovieClip;

    for (var i:int = 1; i < 10; i++)
    {
        nextXPos = i*(boxWidth+boxMargin);

        mc = new MovieClip();
        mc.name = "mc" + i.toString();
        mc.graphics.beginFill(0xff1111);
        mc.graphics.drawRect(nextXPos, 0, boxWidth, boxHeight+boxMargin);
        mc.addEventListener(MouseEvent.CLICK, doButton);

        addChild(mc);

        guideBoxes* = mc;
    }

    trace((guideBoxes[0] as MovieClip).name);
    trace((guideBoxes[1] as MovieClip).name);

    stage.addEventListener(MouseEvent.MOUSE_MOVE, mouseMoveHandler);
    container.addEventListener(MouseEvent.ROLL_OVER, rollOverHandler);
    container.addEventListener(MouseEvent.ROLL_OUT, rollOutHandler);
}