Как остановить функцию во Flash?

function starField(x, y, n) {
for (var i = 0; i<n; i++) {
var star = this.createEmptyMovieClip("star"+i, i);
var dot = star.createEmptyMovieClip("dot", 0);
star._rotation = Math.random()*180;
star._x = x;
star._y = y;
dot.lineStyle(0, 0xFFFFFF, 200);
dot.moveTo(0, 1);
dot.lineTo(0, 0);
dot.onEnterFrame = mover;
dot.speed = Math.random()*100;
}
}
starField(400, 300, 150);

function mover() {
this._y += this.speed;
this._yscale += 10;
this.speed++;
if (this._y>500) {
this._y = 0;
this.speed = Math.random()*10;
this._yscale = 100;
}
}