Colission problem =(

i cannot get this to work for anything. what im trying to do is when movie clip1 runs over movie clip2, it will play movie clip2. (it has a stop on frame 1).

ex: a fist goes past a face, it bleeds.

onClipEvent (enterFrame) {
if (this.hitTest(_root.face)) {
_root.face.play();
}
}

is something wrong here? is it possible to play the movie clip face, with collision.