Actionscript 3.0 Question

Hello,
Look over my script, it displays no error but it also displays no image. What am I doing wrong?

var req:URLRequest = new URLRequest("http://www.treehugger.com/barack-obama-for-president.jpg");
var loader:Loader = new Loader();
loader.load(req);
loader.alpha = 0;
loader.addEventListener(Event.ENTER_FRAME, fade);
addChild(loader);
function fade(event:Event):void
{
	var frames:Number;
	if(loader.alpha < 1)
	{
		if(frames <= 20)
		{
			loader.alpha += 0.05;
		}
	}
	if(loader.alpha >= 1)
	{
		if(frames <= 20)
		{
			frames = 1;
		}
		if(frames > 20)
		{
			if(loader.alpha > 0)
			{
				loader.alpha -= 0.05
			}
			if(loader.alpha <= 0)
			{
				var req:URLRequest = new URLRequest("http://students.georgiasouthern.edu/greeklife/George-W-Bush.jpg");
				var loader:Loader = new Loader();
				loader.load(req);
				loader.alpha = 0;
				frames = 0;
			}
		}
	}
}
	

Code (markup):