UILoader doesn't fill the page

Made the part I’m having problems with bold

import com.greensock.TweenLite;
import com.greensock.easing.*;
import fl.containers.UILoader;

var scrollGallery_mc:UILoader;
var mainPreload:UILoader;
var scrollTimer:Timer = new Timer(2000,1);

Init();
scrollTimer.addEventListener(“timer”,scrollShow);

function Init():void {
mainPreload = new UILoader();
scrollGallery_mc = new UILoader();
mainPreload.load(new URLRequest(“Zombies.swf”));
scrollGallery_mc.load(new URLRequest(“Scroll-Illustration.swf”));
preload_txt.text = “Loading”;
mainPreload.addEventListener(Event.COMPLETE,myComplete);
mainPreload.addEventListener(ProgressEvent.PROGRESS,myProgress);
scrollGallery_mc.addEventListener(Event.COMPLETE,scrollComplete);
addChild(mainPreload);
addChild(scrollGallery_mc);
mainPreload.alpha = 0;
scrollGallery_mc.alpha = 0;

 scrollGallery_mc.x = 31;
 scrollGallery_mc.y = 354;
 scrollGallery_mc.height = 291.1
 scrollGallery_mc.width = 110;

 mainPreload.x = mainPreload.y = 0
 **mainPreload.height = stage.stageHeight;
 mainPreload.width = stage.stageHeight;**

}

stage is set to 700 height/850 width, and I’ve tried that too, but to no avail. Here’s a link to how it appears:

http://mvmdesign.org/Illustration-Zombies.swf