[silin]

по разному может быть:

MovieClip.prototype.flashDown = function () {
	var couleur = new Color(this),m = 255,x = 50;
	this.onEnterFrame = function() {
		m -= x;
		x = Math.round(x*0.8);
		if(m<0) delete this.onEnterFrame;
		else couleur.setBrightOffset(m);
	};
};
mc_1.flashDown();
mc_2.flashDown();