How to dynamically load things into a scroll pane in as4, cs4

Im able to dynamically create a scroll pane, and set its source to be one of the library movieclip symbol stored in the libray off couse and it works but it does not scroll even though the content well goes over the limited allocated space of the scroll pane.

//this creates the scroll pane and pasted on frame one on the main
var sp:ScrollPane = new ScrollPane();
sp.setSize(400,200);
sp.source = them;
sp.name = “sp”;
this.addChild(sp);

//“them” is a movie clip symbol which loads an xml file proccess it shows a few images…
its code below

import fl.controls.*;
var xmlLoader:URLLoader = new URLLoader();
var xmlData:XML = new XML();
xmlLoader.addEventListener(Event.COMPLETE, LoadXML);
xmlLoader.load(new URLRequest(“module1scene.xml”));
function LoadXML(e:Event):void {
xmlData = new XML(e.target.data);
ParseBooks(xmlData);
}

function ParseBooks(bookInput:XML):void {

var allOfThem:XMLList = bookInput.item;
var i:uint = 0 ;
for each (var stuff:XML in allOfThem) {
var imgLoader:Loader = new Loader();
imgLoader.load(new URLRequest(stuff.img));
imgLoader.y = i ;
addChild(imgLoader);
i = i+80;
}
}

I guess what im trying to do was to from the “theme” symbol, inside of it, in the codes, id like to refresh the pane after contents have been added and Im having a hard time tring to call or reference the scrollpane from inside this symbol…but maybe this is a wrong approach…

How do I get it to work? Any solution even not along my lines of thoughts welcome. This was just my first approach to taclking this situation.