４scandalsのサイトのトップにある徐々に消えていく線を
作りたいと色々試しているのですがうまくいきません

this.createEmptyMovieClip("target", 1);
target._x = Stage.width/2;
target._y = Stage.height/2;
target.lineNum = 0;
target.onEnterFrame = function():Void {
	this.xPos = this._x;
	this.yPos = this._y;
	this._x = _xmouse;
	this._y = _ymouse;
	this.lineNum ++;
	drawLine(this);
};
function drawLine(target_mc:MovieClip):Void {
	var lineNum = target_mc.lineNum;
	this.createEmptyMovieClip("line"+lineNum, lineNum+1);
	var line_mc = this["line"+lineNum];
	line_mc.lineStyle(1, 0xFFFFFF);
	line_mc.moveTo(target_mc.xPos, target_mc.yPos);
	line_mc.lineTo(target_mc._x, target_mc._y);
	line_mc.onEnterFrame = function():Void {
		this._alpha -= 2;
		if (this._alpha <= 0) {
			this.removeMovieClip();
		}
	};
}

	(前略)
var deceleration:Number = 0.1;
target.onEnterFrame = function():Void {
	this.xPos = this._x;
	this.yPos = this._y;
	this._x += (_xmouse - this._x)*deceleration;
	this._y += (_ymouse - this._y)*deceleration;
	this.lineNum ++;
	drawLine(this);
};
	(後略)

onClipEvent (load) {
	_x = _xmouse;
	_y = _ymouse;
	r    = 0;
	dist = 0;
	gain = 0.98;
}

onClipEvent (enterFrame) {
	dx = dist * Math.cos(r) + _xmouse/60;
	dy = dist * Math.sin(r) + _ymouse/60;
	_x += dx;
	_y += dy;
	r    = Math.atan2(dy,dx);
	dist = Math.sqrt(dx*dx+dy*dy) * gain;
}