What's wrong with this preloader?

normally when i do a preloader i did something simple like this:

this.onEnterFrame = function() {
var ammount:Number = this.getBytesLoaded()/this.getBytesTotal()*100;
loader.loadbar._xscale = ammount;
if (ammount == 100) {
this.gotoAndPlay(2);
}
};

but now i’m trying something new but i just don’t get how it works. i’ve posted my flash file, it’s something i’ve gotten from kirupa, just trying to change it and try something new but it doesn’t work.
please help!