Problem resizing proportionately

OK, I’ve tried a few different but similar methods of resizing background images in a movie clip to take up the full size of the browser. They work, but the problem is the photos aren’t resizing proportionately. I’m trying to pull off something more like redtettemer.com
where the image stretches and the other side goes off screen to keep the proportions.
Heres a couple versions of the code I tried:

Portfolio_bg is the movie clip that calls in swf files which contain background animations and images.

Stage.align = “TL”;
Stage.scaleMode = “noScale”;

//All movie clips you then use will automatically NOT scale. To get them to scale add this code to your actions layer:

portfolio_bg._xscale = Stage.width *.10;
portfolio_bg._yscale = Stage.height *.15;

stageListener = new Object();
// Create a function for the event you want to listen for
stageListener.onResize = function ()
{
portfolio_bg._xscale = Stage.width *.10;
portfolio_bg._yscale = Stage.height *.15;

// Code for response to browser resizing here
}
// Assign a listener for the Stage object
Stage.addListener(stageListener);

aaaand attempt number 2:

//scale stage background with browser window
Stage.scaleMode = “noScale”;
Stage.align = “TL”;

var stageListener:Object = new Object ();
stageListener.onResize = positionContent;
Stage.addListener(stageListener);

function positionContent():Void {
portfolio_bg._width = Stage.width;
portfolio_bg._height = Stage.height;

}

positionContent();

any help would be much appreciated as I’ve been working on this for a while.