Stopping kirupa's infinite menu

does anyone know how to make kirupa’s infinite menu (http://www.kirupa.com/developer/mx/infinite.htm), work only when the mouse is over the movie clip???

here’s the actionscript:

onClipEvent (load)
{
xcenter=150;
speed=1/10;
}
onClipEvent (enterFrame)
{
var distance=_root._xmouse-xcenter;
_x+=(distance*speed);
}

onClipEvent (enterFrame)
{
var distance=_root._xmouse-xcenter;
_x+=(distance*speed);
if (_x > 0) _x=-300;
if (_x < -300) _x=0;
}