How do I write the listener in a class?

programming flash
1

I want to add a listener to two textfields in an mc, not sure how to change the function to work properly in a class. The mc has a class associated to it. I have included the code below.

Thanks for any help

The error I get for each function

 
Line 23: '(' expected
		 function description.onChanged(textfield_txt:TextField) {
Line 20: The same member name may not be repeated more than once.
		 function titlename.onChanged(textfield_txt:TextField) {


class Note extends MovieClip {
	var x:Number;
	var y:Number;
	public var titlename:TextField;
	public var description:TextField;
	public var txtListener:Object = new Object();
	   
	public function Note() {
		titlename.value = "Enter Your Title";
		description.value = "Enter Your Description";
		trace("+++++++");
		titlename.addListener(txtListener);
		description.addListener(txtListener);
		}
	function setInfo() {
	}
	function getInfo() {
	}
	
	function titlename.onChanged(textfield_txt:TextField) {
		trace(textfield_txt._name+" changed");
	};
	function description.onChanged(textfield_txt:TextField) {
		trace(textfield_txt._name+" changed");
	};
	function txtListener.onChanged(textfield_txt:TextField) {
		trace(textfield_txt._name+" changed and notified myListener");
	};
}