Reference to stage in document class throwing error when loaded in preloader

Hi, assistance greatly appreciated.

I have buils a flash movie using a document class, all works fine. When I load the movie using a preloader all reference to the stage as in stage.scaleMode = StageScaleMode.NO_SCALE; or stage.stageHeight throws a TypeError: Error #1009: I think i undrestand the problem, I am no longer accessing the stage properties.

How do i access stage properties from the document class once loaded into the prelaoder?

Kind regards

Patrick

code snippet:

 
public function WelMain() {
   xmlFile_base = "http://welgedacht.dev.office/php/flash/";
   imageDir = "http://welgedacht.dev.office/images/";
   setStage(); 
   callServer(1);
   nodeArray = new Array();
   setArray = new Array();
 
  } //end constructor 
 
private function setStage():void {
   stage.scaleMode = StageScaleMode.NO_SCALE; //throws error
   stage.align = StageAlign.TOP_LEFT; // throws error
   //declare stage elements
   ic_mc = new mc_interfaceContainer();
   leftBgMain_mc = new mc_navBg;
   bigSun_mc = new mc_bigSun();
   leftBgSub_mc = new mc_navBg();
   activitiesBg_mc = new mc_navBg();
   //add interface container
   addChild(ic_mc);
   ic_mc.width = stage.stageWidth; // throws error
   var icHeight:Number = stage.stageHeight; // throws error
...
}