ActionScript 2.0 :: HitTest To Check If Cursor Is On Navigation

I have written a little script for a navigation menu and basically all I want to do is to use hitTest to check if the cursor is on the navigation, and if so I want to play a simple shape tween opening animation, and if the cursor is out of the navigation I want to play a shape tween closing animation sounds simple enough right? But for some reason it doesn't run through the animation it just going there and stops, well here's the code..

Code:
onClipEvent (enterFrame) {
var Mousex = _root._xmouse;
var Mousey = _root._ymouse;
if (this.hitTest(Mousex,Mousey)) {
this.gotoAndPlay("On");
} else {
this.gotoAndPlay("Off");
}}

I've included a screen capture of the animation as well.