Mouse if statement[AS2 flashCS4]

Hello All,

I have an if statement that says:


this.onEnterFrame = function()
{
if(_root._xmouse >= 612)
  {
     fadeMovieClip(100, 0);
     trace("itWorks");
   }
}

the fadeMovieClip function is this:

function fadeMovieClip(startAt:Number, endAt:Number):Void 
{
var myTween:Tween = new Tween(_root.Car_3d.DOF,"_alpha",mx.transitions.easing.None.easeNone, startAt, endAt,.5, true);
}

I get a trace but the tween does not happen. Does anyone know why?

Thanks in advance,
neonreel