Preloader stops buttons from working?!

Question

Hi,
I made a flash file with buttons that go here and there and everything was fine
except it takes a while to load so i added a preloader and suddenly the compiler
is throwing the following error:
Error #1009: Cannot access a property or method of a null object reference.
... and the buttons have ceased to function.
Here is my code:
preloader:
import flash.events.ProgressEvent;
function update(e:ProgressEvent):void
var percent:Number = Math.floor( (e.bytesLoaded*100)/e.bytesTotal );
if(preloaderMC is MovieClip){
preloaderMC.gotoAndStop(percent);
if(percent == 100){
play();
loaderInfo.addEventListener(ProgressEvent.PROGRESS, update);
// Extra test for IE
var percent:Number = Math.floor( (this.loaderInfo.bytesLoaded*100)/this.loaderInfo.bytesTotal );
if(percent == 100){
nextFrame();
stop();
scene 1:
stop();
import flash.events.MouseEvent;
//---Hair Button---\\
hair_btn.addEventListener(MouseEvent.CLICK, hairClick);
function hairClick(event:MouseEvent):void{
    gotoAndStop("4");
//---Home Button---\\
home_btn.addEventListener(MouseEvent.CLICK, homeClick);
function homeClick(event:MouseEvent):void{
    gotoAndStop("1");
//---Contact Button---\\
weddings_btn.addEventListener(MouseEvent.CLICK, weddingsClick);
function weddingsClick(event:MouseEvent):void{
    gotoAndStop("3");
//---Products Button---\\
products_btn.addEventListener(MouseEvent.CLICK, productsClick);
function productsClick(event:MouseEvent):void{
    gotoAndStop("2");
//---Gallery Button---\\
gallery_btn.addEventListener(MouseEvent.CLICK, galleryClick);
function galleryClick(event:MouseEvent):void{
    gotoAndStop("5");
//---Contact Button---\\
contact_btn.addEventListener(MouseEvent.CLICK, contactClick);
function contactClick(event:MouseEvent):void{
    gotoAndStop("6");
Please help me sort this out!
Thanks

Answer 1

If you are getting a 1009 error, the file will not work, so the buttons might not be the problem.
The 1009 error indicates that one of the objects being targeted by your code is out of scope.  This could mean that the object....
- is not in the display list
- doesn't have an instance name (or the instance name is mispelled)
- does not exist in the frame where that code is trying to talk to it
- is animated into place but is not assigned instance names in every keyframe for it
- is one of two or more consecutive keyframes of the same objects with no name assigned in the preceding frame(s).
If you go into your Publish Settings Flash section and select the option to Permit debugging, your error message should have a line number following the frame number which will help you isolate which object is involved.