Actionscript 3.0 Question

1

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;
            }
        }
    }
}