hitTest bounding box issue

programming flash
1

hi there,
Having some trouble using hitTest here.

I have a movie clip with a circle shape inside it on the stage, and I have a movie clip called pointer that is dragable.

When I drag the pointer movie clip onto the circle movie clip, it is the bound box of the movie clip that is the target, this means the square surrounding the circle movie clip is all being targeted but I only want the actual circle shape to act as the hit Area.

Anyone know how to just have the movie clip content as the hit Area?
cheers:)

here is a link:
http://webfirst.no/hittest/

here is the code:
[COLOR=Blue]

[/COLOR][COLOR=Blue]_root.ball._alpha = 25;
_root.pointer.onPress = function():Void {
_root.pointer.startDrag();
_global.nCheckHit = setInterval(fnCheckHit, 5);
};
_root.pointer.onRelease = function():Void {
_root.pointer.stopDrag();
clearInterval(nCheckHit);
};

function fnCheckHit():Void {

if (_root.pointer.hitTest(_root.ball)) {
    trace("Hit");
    _root.ball._alpha = 100;
}
if (!_root.pointer.hitTest(_root.ball)) {
    trace("No Hit");
    _root.ball._alpha = 25;
}

}[/COLOR]