Page Flip again

I know the issue has been posted before but I could not really find the step by step tut explaining the trick. Anyway, you may know the fla, I would like to add some more pages to the book (there are 8 MCs now) but I cannot figure out how to do it - which part of the AS is responsible for that? I am gazing at the code like a drunk cow but cannot find the solution. Please help anyone or else I will post my nude pic here.

cheers