Help! Urgent! UILoader

do anyone know how to load in an UIloader purely with action script withoud dragging it onto the stage?

I have try the following code but it just can not work

import fl.containers.UILoader

var bg:UILoader = new UILoader();
bg.source = “Element/front page.jpg”
addChild (bg);

(the above code only works when I drag an UIloader to the stage and delete it)