Template Frustration

Can anyone please help me as I struggle to learn flash mx. I used a tutorial that I had seen to create a scrolling menu that I liked but am unable to sort out what I need to do to increase the stage from 500px to 690px and the movie to be 50% wider and still play the whole thing. I have tried a few things and managed to widen the document and the width of the movie but it didn’t then play the whole width so I thinnk it’s in the action script which is quite short but I’m obviously not understanding whats happening in it.

I have attached the fla if anyone can help.