Converting a Bitmap loader to a Movieclip loader - (Flash/AS3)

import caurina.transitions.Tweener;
 
var btn:Object;
var disabledBtn:Object;
 
var currentPage:* = null;
var nextPage:* = null;
 
var loader:Loader;
var urlRequest:URLRequest;
 
//reference to all the buttons on the stage
var buttons:Array = new Array (b1, b2, b3, b4, b5, b6);
 
//this array holds all the names we want to use for our buttons
var button_name:Array = new Array ("Home", "About Us", "Selected Work", "References", "Jobs", "Contact");
 
//this array stores which images we want to load
var images_array:Array = new Array ("images/pic1.jpg","images/pic2.jpg","images/pic3.jpg","images/pic4.jpg","images/pic5.jpg","images/pic6.jpg");
 
for (var i:String in buttons) {
	buttons[i].button_txt.txt.text = button_name[i];
	buttons[i].alpha = .25;
	buttons[i].currentPage = images_array[i];
	buttons[i].buttonMode = true;
	buttons[i].button_txt.mouseChildren = false;
	
	buttons[i].addEventListener(MouseEvent.MOUSE_OVER,onOVER);
	buttons[i].addEventListener(MouseEvent.MOUSE_OUT,onOUT);
}
 
function onOVER(event:MouseEvent):void {
	btn = event.currentTarget;
	Tweener.addTween(btn, {alpha:1, time: 1});
	disableBtn(btn);
}
function onOUT(event:MouseEvent):void {
	btn = event.currentTarget;
	Tweener.addTween(btn, {alpha:.25, time: 1});
}
 
function disableBtn(btn:Object):void {
	loader = new Loader();
	urlRequest = new URLRequest(btn.currentPage);
 
	loader.load(urlRequest);
	loader.contentLoaderInfo.addEventListener(Event.COMPLETE, isLoaded);
	loader.x = 50;
	loader.y = 0;
}
 
function isLoaded(ev:Event):void {
	if (currentPage == null) {
		currentPage = ev.currentTarget.content;
		currentPage.alpha = 0;
		addChild(loader);
		fadeIn(currentPage);
	} else {
		nextPage = ev.currentTarget.content;
		fadeOut(currentPage);
	}
}
 
function fadeIn(who:*):void {
	Tweener.addTween(who, {alpha:1, time: 1});
	currentPage = nextPage;
}
 
function fadeOut(who:*):void {
	Tweener.addTween(who, {alpha:1, time: 1, onComplete:fadeIn, onCompleteParams:currentPage});
}
 
stop();