Something

var xmlRequest:URLRequest = new URLRequest("imageData.xml");
var xmlLoader:URLLoader = new URLLoader(xmlRequest);
var imgData:XML;
var imageLoader:Loader;
var rawImage:String;
var rawH:String;
var rawW:String;
var imgNum:Number = 0;
var checkSec:Timer = new Timer(100);
var numberOfChildren:Number;

xmlLoader.addEventListener(Event.COMPLETE, xmlLoadedF);

master_MC.addEventListener(MouseEvent.CLICK, nextImgF);
master_MC.buttonMode = true;

//navigation buttons
next_btn.addEventListener(MouseEvent.CLICK, nextImgF);
next_btn.buttonMode = true;
prev_btn.addEventListener(MouseEvent.CLICK, prevImgF);
prev_btn.buttonMode = true;

function xmlLoadedF(event:Event):void{
	checkSec.start();
	checkSec.addEventListener(TimerEvent.TIMER,checkerF);
	imgData = new XML(event.target.data);
}
function packagedF():void{
checkSec.removeEventListener(TimerEvent.TIMER,checkerF);
rawImage = imgData.image[imgNum].imgURL;
numberOfChildren = imgData.*.length();
rawW = imgData.image[imgNum].imgW;
rawH = imgData.image[imgNum].imgH;
imageLoader = new Loader;
imageLoader.load(new URLRequest(rawImage));
master_MC.addChild(imageLoader);
imageLoader.x = (stage.stageWidth - Number(rawW)) /2;
// imageLoader.y = (stage.stageHeight - Number(rawH)) /2;
}
function checkerF(event:TimerEvent):void{
if(imgNum == 0) {
packagedF();
}else if (imgNum < numberOfChildren) {
imageLoader.unload();
packagedF();
}else{
imageLoader.unload();
imgNum = 0;
packagedF();
}
}
function nextImgF(event:MouseEvent):void{
imgNum++;
checkerF(null);
}
function prevImgF(event:MouseEvent):void{
imgNum = (imgNum-1+numberOfChildren)%numberOfChildren;
checkerF(null);
}