Listeners for Scrollbar

Hello, Im trying to make a scrollbar…>

First off, I want to make full use of Listeners (of which I never usually use! - so I need to learn). This will enable smooth scrolling, and also allows the mouse to be off the ‘MC’ once it has been clicked, whilst still allowing _y scrolling.

I will be adding more of my code when I get over my initial hurdle, which is simply adding a listener to the Mouse Down event.
I want to add another listener to the Stage - for when the mouse is UP, allowing the mouse not to be over the MC which is acting as the scroller of the scroll bar. is the MC for clickable region of the scrollbar.

var yOffset:Number;
var MDListener:Object = new Object();
var MUListener:Object = new Object();

MDListener.onMouseDown = function(){
	yOffset = _ymouse -;
MUListener.onMouseUp = function(){

Alas - nothing is happening as yet - but that will be to come.
What I would like to know IS - Am I connecting a listener to fire when my mouse clicks on my MC? and does it remove itself when I release the mouse?

Thanks - Help would be to die for!