this.stop();
this.addEventListener(MouseEvent.MOUSE_OVER,mover);
this.addEventListener(MouseEvent.MOUSE_OUT,mout);

function mover(e:MouseEvent):void {
    stopPlayReverse();
    this.play();
}

function mout(e:MouseEvent):void {
    this.addEventListener(Event.ENTER_FRAME, playReverse, false, 0, true);
}

function playReverse(e:Event):void {
    if (this.currentFrame == 1) {
        stopPlayReverse();
    } else {
        this.prevFrame();
    }
}

function stopPlayReverse():void {
    if (this.hasEventListener(Event.ENTER_FRAME)) {
        this.removeEventListener(Event.ENTER_FRAME, playReverse);
    }
}