Tacking this preloader on almost working - what's missing?

Question

Hi
I found a cool preloader tutorial with a free preloader which I added onto my flash project.  I did it by creating a new scene before my project scene, and adding the preloader to it.
The pre loader works fine, and my project all worked fine before I put the preloader on, but now after the preloader finishes, my site's buttons won't work and in Flash CS4 there is a compiler error:
TypeError: Error #1009: Cannot access a property or method of a null object reference.
    at website_fla::MainTimeline/frame2()
Take the preloader scene away, and my site works fine again.
Any idea what I need to do to make them work together?
Cheers
Shaun

Answer 1

Sorry - here it is:
01.import flash.events.ProgressEvent;
02.function update(e:ProgressEvent):void
03.{
04. var percent:Number = Math.floor( (e.bytesLoaded*100)/e.bytesTotal );
05. if(preloaderMC is MovieClip){
06. preloaderMC.gotoAndStop(percent);
07. }
08. if(percent == 100){
09. play();
10. }
11.}
12.loaderInfo.addEventListener(ProgressEvent.PROGRESS, update);
13.// Extra test for IE
14.var percent:Number = Math.floor( (this.loaderInfo.bytesLoaded*100)/this.loaderInfo.bytesTotal );
15.if(percent == 100){
16. nextFrame();
17.}
18.stop();
and here's the page it came from:
http://www.flashmagazine.com/tutorials/detail/how_to_make_a_custom_as3_preloader/
Cheers