[F8] onRollover play attached movie clip??

[gtomescu]

I'm trying to attach a movie clip and to play that movie clip on rollover. At this point the movie is being attached, but the rollover/rollout functions don't work!

What am I missing here? See code below.
Thanks in advance!

onEnterFrame = function () {
    _root.attachMovie("menu","menu_mc",1, {_x:0,_y:200})
    menu_mc.onRollOver = function () {
        this.play();
        delete menu_mc.onEnterFrame;
    }
    menu_mc.onRollOut = function () {
        this.onEnterFrame = function() {
        menu_mc.prevFrame();
    }
    }
}