[RESOLVED] Why does this code crash Flash?

[_Ric_]

I'm sure I should be able to do this kind of thing by now, but heck - looks like I can't. I very rarely write custom classes - and this bit of code crashing Flash without any error messages is probably why. Can anyone tell me what I've done wrong?

I have a movieclip in my Flash library which contains a textfield. For the linkage, I have set it to com.CustomTitle which points it to this class file:

package com{
    
    import flash.display.*;
    import flash.text.*;
	
    dynamic public class CustomTitle extends MovieClip{
       
        public var txt:String;
        public var newText:String;
        public var n:uint;
        public var char:String;

        public function CustomTitle(){
            
            txt = this.name;
            newText = "";
            n = 0;
            while (n < txt.length){
                char = txt.charAt(n);
                if (char != "_"){
                    newText = newText + char;
                }else{
                    newText = newText + " ";
                }
	    n ++;
            }
            this.text = newText;
            return;
        }   
    }
}

It's meant to replace the text in the movieclip with it's own instance name, substituting underscores for spaces.

Thanks.

[_Ric_]

Ignore me - this.text was meant to be this.textField.text. Duh!