Some AS help?

I’m using the code from the dynamic transition tutorial on kirupa but I want to know what code do I add (and where?) to make a preloader visible (loadbar)?

this is the code

onClipEvent (enterFrame){
if(this.getBytesLoaded() == this.getBytesTotal()){

What do you add to make a loadbar? please can someone help I’m stumped!

Thanks guys.