back button help!

[xxaerisxx]

i followed my teacher's instruction but my back button in my flash game isnt working >.< its from CS5 can any one help?
the error is
TypeError: Error #1009: Cannot access a property or method of a null object reference.
at Adrianti_tontowifinal_fla::MainTimeline/frame233()
here is my .fla file
http://www.sendspace.com/file/irgux1

[Steven FN]

It seems like everything works, but you needed to move the AS3 Frame on 233 to 234 to have the actions affect the object (backBtn) its looking for. I would also change the backPressed function to the below:

function backPressed(evt:MouseEvent): void
{
gotoAndPlay("start");
}

If you are using the same backBtn, i would suggest creating a new layer for it, and using the same button for all three layers (credits, game, options).

Also in frame 1, you don't need "stage.addChild(pointer);" you should delete that line, because the pointer is already on the stage, and once the backBtn worked it created duplicate pointers.