Not centering on stage, why?

Question

Hello again folks. I've come across a new snag to a previous project. I'm not quite sure why, but when the full image is loaded to the stage, it is not centering it properly. The trace of fullLoader returns "0" for the width and height of the full-sized image, and I'm not quite sure how to pass the necessary information into the showPicture function so that it correctly centers the image. I tried tracing the content of fullLoader and got an error message. Any help would be appreciated.
import flash.display.*;
import fl.transitions.Tween;
import fl.transitions.easing.*;
import flash.filters.*;
var fadeTween:Tween;
var imageLoader:Loader;
var fullLoader:Loader = new Loader;
var xml:XML;
//parse XML data as an array
var xmlList:XMLList;
var xmlLoader:URLLoader = new URLLoader();
var thumbDShadow:DropShadowFilter = new DropShadowFilter();
thumbDShadow.color = 0x000000;
thumbDShadow.blurX = 10;
thumbDShadow.blurY = 10;
thumbDShadow.distance = 3;
xmlLoader.load(new URLRequest("data/gallery.xml"));
xmlLoader.addEventListener(Event.COMPLETE, xmlLoaded);
function xmlLoaded(event:Event):void {
    xml = XML(event.target.data);
    //parse the nodes in the XML file
    xmlList = xml.children();
    //count the number of nodes in the XML file via XMLList
    trace(xmlList.length());
    //loop to load all of the thumbnails, based on the number of nodes in XMLList
    for (var i:int = 0; i < xmlList.length(); i++) {
        imageLoader = new Loader();
        imageLoader.load(new URLRequest(xmlList[i].attribute("thumb")));
        //position of thumbs (horizontally across stage)
        imageLoader.x = i * 110 + 10;//thumbs are 100 x 100 so, +10 to the width, plus +10 from left edge
        imageLoader.y = 10;
        imageLoader.name = xmlList[i].attribute("source");
        imageLoader.filters = [thumbDShadow];
        //add thumbnails to stage
        addChild(imageLoader);
        //set up thumbs to load primary image
        imageLoader.addEventListener(MouseEvent.CLICK, showPicture);
function showPicture(event:MouseEvent):void {
    fullLoader.unload();
    fullLoader.load(new URLRequest(event.target.name));
    //position full image below the row of thumbs and center to stage
    fullLoader.x = (stage.stageWidth - fullLoader.width) * 0.5;
    fullLoader.y = (stage.stageHeight - fullLoader.height) * 0.5;
    addChild(fullLoader);
    fadeTween = new Tween(fullLoader, "alpha", None.easeNone, 0, 1, 0.5, true);
    trace("Stage: " + stage.stageWidth + " wide by " + stage.stageHeight + " tall.");
    trace("FullLoader is: " + fullLoader.width + " wide by " + fullLoader.height + " tall.");

Answer 1

OH! Wow, okay now this makes much more sense now. The amended showPicture function is now:
function showPicture(event:MouseEvent):void {
    fullLoader.unload();
    fullLoader.load(new URLRequest(event.target.name));
    fullLoader.contentLoaderInfo.addEventListener(Event.COMPLETE, addToStage);
    function addToStage(event:Event):void {
        //position full image below the row of thumbs and center to stage
        fullLoader.x = (stage.stageWidth - fullLoader.width) * 0.5;
        fullLoader.y = (stage.stageHeight - fullLoader.height) * 0.5 + 110;
        addChild(fullLoader);
        fadeTween = new Tween(fullLoader, "alpha", None.easeNone, 0, 1, 0.5, true);
        trace("Stage: " + stage.stageWidth + " wide by " + stage.stageHeight + " tall.");
        trace("FullLoader is: " + fullLoader.width + " wide by " + fullLoader.height + " tall.");
AWESOME! Thanks so much for your help!