help with as3 image carousel

//We use 70x70 sized images (change this if different for your images)
const IMAGE_WIDTH:uint = 70;
const IMAGE_HEIGHT:uint = 70;

//Set the focal length
var focalLength:Number = 400;

//Set the vanishing point
var vanishingPointX:Number = stage.stageWidth / 2;
var vanishingPointY:Number = stage.stageHeight / 2;

//The 3D floor for the images
var floor:Number = 20;

//We calculate the angleSpeed in the ENTER_FRAME listener
var angleSpeed:Number = 0;

//Radius of the circle
var radius:Number = 200;

//Specify the path to the XML file.
//You can use my path or your own.
var xmlFilePath:String = "3D-carousel-settings.xml";

//We save the loaded XML to a variable
var xml:XML;

//This array will contain all the imageHolders
var imageHolders:Array = new Array();

//We want to know how many images have been loaded
var numberOfLoadedImages:uint = 0;

//The total number of images according to XML file
var numberOfImages:uint = 0;

//Load the XML file.
var loader = new URLLoader();
loader.load(new URLRequest(xmlFilePath));

//We call the function xmlLoaded() when the loading is complete.
loader.addEventListener(Event.COMPLETE, xmlLoaded);

//This function is called when the XML file is loaded
function xmlLoaded(e:Event):void {

    //Create a new XML object from the loaded XML data
    xml = new XML(loader.data);
    xml.ignoreWhitespace = true;

    //Call the function that loads the images
    loadImages();
}

//This function loads and creates holders for the images specified in the 3D-carousel-settings.xml
function loadImages():void {

    //Get the total number of images from the XML file
    numberOfImages = xml.number_of_images;

    //Loop through the images found in the XML file
    for each (var image:XML in xml.images.image) {

        //Create a new image holder for an image
        var imageHolder:MovieClip = new MovieClip();

        //Create a loader that will load an image
        var imageLoader = new Loader();

        //Add the imageLoader to the imageHolder
        imageHolder.addChild(imageLoader);

        //We don't want to catch any mouse events from the loader
        imageHolder.mouseChildren = false;

        //Position the imageLoader so that the registration point of the holder is centered
        imageLoader.x = - (IMAGE_WIDTH / 2);
        imageLoader.y = - (IMAGE_HEIGHT / 2);

        //Save where the imageHolder should link to
        imageHolder.linkTo = image.link_to;

        //Add the imageHolder to the imageHolders array
        imageHolders.push(imageHolder);

        //Load the image
        imageLoader.load(new URLRequest(image.url));

        //Listen when the image is loaded
        imageLoader.contentLoaderInfo.addEventListener(Event.COMPLETE, imageLoaded);
    }
}

//This function is called when an image is loaded
function imageLoaded(e:Event):void {

    //Update the number of loaded images
    numberOfLoadedImages++;

    //Set the bitmap smoothing to true for the image (we know that the loader's content is a bitmap).
    e.target.content.smoothing = true;

    //Check to see if this is the last image loaded
    if (numberOfLoadedImages == numberOfImages) {

        //Set up the carousel
        initializeCarousel();
    }
}

//This function is called when all the images have been loaded.
//Now we are ready to create the 3D carousel.
function initializeCarousel():void {

    //Calculate the angle difference between the images (in radians)
    var angleDifference:Number = Math.PI * (360 / numberOfImages) / 180;

    //Loop through the images
    for (var i:uint = 0; i < imageHolders.length; i++) {

        //Assign the imageHolder to a local variable
        var imageHolder:MovieClip = (MovieClip)(imageHolders[i]);

        //Get the angle for the image (we space the images evenly)
        var startingAngle:Number = angleDifference * i;

        //Position the imageHolder
        imageHolder.xpos3D = radius * Math.cos(startingAngle);
        imageHolder.zpos3D = radius * Math.sin(startingAngle);
        imageHolder.ypos3D = floor;

        //Set a "currentAngle" attribute for the imageHolder
        imageHolder.currentAngle = startingAngle;

        //Calculate the scale ratio for the imageHolder (the further the image -> the smaller the scale)
        var scaleRatio = focalLength/(focalLength + imageHolder.zpos3D);

        //Scale the imageHolder according to the scale ratio
        imageHolder.scaleX = imageHolder.scaleY = scaleRatio;

        //Set the alpha for the imageHolder
        imageHolder.alpha = 0.3;

        //We want to know when the mouse is over and out of the imageHolder
        imageHolder.addEventListener(MouseEvent.MOUSE_OVER, mouseOverImage);
        imageHolder.addEventListener(MouseEvent.MOUSE_OUT, mouseOutImage);

        //We also want to listen for the clicks
        imageHolder.addEventListener(MouseEvent.CLICK, imageClicked);

        //Position the imageHolder to the stage (from 3D to 2D coordinates)
        imageHolder.x = vanishingPointX + imageHolder.xpos3D * scaleRatio;
        imageHolder.y = vanishingPointY + imageHolder.ypos3D * scaleRatio;

        //Add the imageHolder to the stage
        addChild(imageHolder);
    }

    //Add an ENTER_FRAME for the rotation
    addEventListener(Event.ENTER_FRAME, rotateCarousel);
}

function rotateCarousel(e:Event):void {

    //Calculate the angleSpeed according to mouse position
    angleSpeed = (mouseX - vanishingPointX) / 4096;

    //Loop through the images
    for (var i:uint = 0; i < imageHolders.length; i++) {

        //Assign the imageHolder to a local variable
        var imageHolder:MovieClip = (MovieClip)(imageHolders[i]);

        //Update the imageHolder's current angle
        imageHolder.currentAngle += angleSpeed;

        //Set a new 3D position for the imageHolder
        imageHolder.xpos3D=radius*Math.cos(imageHolder.currentAngle);
        imageHolder.zpos3D=radius*Math.sin(imageHolder.currentAngle);

        //Calculate a scale ratio
        var scaleRatio = focalLength/(focalLength + imageHolder.zpos3D);

        //Scale the imageHolder according to the scale ratio
        imageHolder.scaleX=imageHolder.scaleY=scaleRatio;

        //Update the imageHolder's coordinates
        imageHolder.x=vanishingPointX+imageHolder.xpos3D*scaleRatio;
        imageHolder.y=vanishingPointY+imageHolder.ypos3D*scaleRatio;
    }

    //Call the function that sorts the images so they overlap each others correctly
    sortZ();
}

//This function sorts the images so they overlap each others correctly
function sortZ():void {

    //Sort the array so that the image which has the highest
    //z position (= furthest away) is first in the array
    imageHolders.sortOn("zpos3D", Array.NUMERIC | Array.DESCENDING);

    //Set new child indexes for the images
    for (var i:uint = 0; i < imageHolders.length; i++) {
        setChildIndex(imageHolders[i], i);
    }
}

//This function is called when the mouse is over an imageHolder
function mouseOverImage(e:Event):void {

    //Set alpha to 1
    e.target.alpha=1;
}

//This function is called when the mouse is out of an imageHolder
function mouseOutImage(e:Event):void {

    //Set alpha to 0.3
    e.target.alpha=0.3;
}

//This function is called when an imageHolder is clicked
function imageClicked(e:Event):void {

    //Navigate to the URL that is in the "linkTo" variable
    navigateToURL(new URLRequest(e.target.linkTo));
}