Matrix text effect problem

1

Hey all,
I’m trying to create a matrx text effect for the background of a gallery. I found a great example from [font=Verdana][size=1][color=#99b3c1]ilyaslamasse (pom) aka ilyas usal, [/color][/size][/font]
and modified the actionscript to what i wanted. only problem: no matter what i try, it ends up using 100% of the CPU after mere seconds. as you can see, this would be a problem in the long-run.

for my first keyframe i have:

/***Author: Ilyas USAL (pom)
	Title: The Matrix has you...
	Date: 06/06/2003
	Version: 2 -- Japanese characters, and it fades from white to green
***/
// To make it run smoother
_quality = "LOWEST";

// String containing all the characters available in the font
letters_str = "unrealtournament,;:!?./$" ;
length_num = letters_str.length ;

for the next layer and kayframe i have:

/*** Functions ***/
// fade out and remove clip when _alpha inferior to 10 - no parameters
function fadeToBlack(){
	this._alpha -= 5;
	if (this._alpha < 10){
		delete this.onEnterFrame;
		this.removeMovieClip();
	}
};
// color fade from white to the original color
function whiteToGreen(){
	this._alpha -= 5;
	if (this.rb < 2 && this.gb < 2 && this.bb < 2){
		this.rb = this.gb = this.bb = 0;
		delete this.onEnterFrame;
	}
	else {
		this.rb *= .9;
		this.gb *= .9;
		this.bb *= .9;
	}
	var trans = {rb:this.rb , gb:this.gb , bb:this.bb};
	this.col.setTransform(trans);
};
// Create a new clip with a letter in it
// x: _x position ; y: _y position ; size: size of the letter
MovieClip.prototype.createLetter = function (x,y,size){
	// Create and position the new clip
	var mc = this.createEmptyMovieClip("letter"+this.dep,this.dep++);
	mc._x = x;
	mc._y = y;
	// Create a new TextField in the clip
	mc.createTextField("t",0,0,0,size,size);
	// Choose a random letter
	var myChar = letters_str.charAt(random(length_num));
	mc.t.text = myChar;
	// Create the TextFormat, format the text and embed the font
	var tf = new TextFormat();
	tf.size = size;
	tf.font = "Katakana";
	tf.selectable = false;
	tf.color = "0x00ff00";
	mc.t.setTextFormat(tf);
	mc.t.embedFonts = true;
	// Letter goes from white to green 
	mc.rb = mc.gb = mc.bb = 255;
	mc.col = new Color (mc) ;
	mc.col.setTransform({rb:255 , gb:255 , bb:255});
	mc.onEnterFrame = whiteToGreen;
};
// Create a trail of letters
function createTrail(){
	// Create new clip and position it randomly
	var clip = this.createEmptyMovieClip("trail"+i,i++);
	clip._x = Math.round(random(Stage.width)/20)*20;
	clip._y = clip.y = -20;
	// Choose a random size for the letters, and set the spacing
	var size = random(20)+15;
	clip.spacing = size ;
	// onEnterFrame, create a new letter that will wade out.
	// if we're at the bottom of the screen, fade out the whole trail
	clip.onEnterFrame = function(){
		this.y += this.spacing;
		this.createLetter(0,this.y,size);
		if (this.y > Stage.height) this.onEnterFrame = fadeToBlack;
	};
};

and for the final layer and keyframe i have:

// Create a new trail every 100 milliseconds
setInterval(this,"createTrail",100);

here’s a sample i exported: matrix swf

any help?
[font=Arial][size=2]
[/size][/font]