Проблема такова - не запускается сточка this.removeMovieClip();

Код:
var grad = 0;
var step = 0.25;
var rad = 10;
var dep = 1;
ball_mc.radMove = function() {
grad += (step/Math.PI*180)/50;
this._x += Math.cos(grad)*rad;
this._y += Math.sin(grad)*rad;
rad -= 1;
if (rad<=0) {
rad = 30;
}
this.duplicate();
};
ball_mc.duplicate = function() {
dep += 1;
var dupe = this.duplicateMovieClip("dupe"+dep, dep++);
dupe.onEnterFrame = this._parent.deleteIT();
};
function deleteIT() {
this._xscale -= 2;
this._yscale -= 2;
if (this._xscale<=0) {
this.removeMovieClip();
}
}
ball_mc.onEnterFrame = ball_mc.radMove;