Sliding windows in Flash

Can anyone tell me why I cannot get the buttons on the first scene to slide the pages through the mask?

The only thing that I can notice (http://www.katewolfmuller.com/xx/action_frame.jpg) that when I create the movie clip symbol that it doesn’t appear in the Action Script Panel under “Symbol Definition/s”

Please help!!! :sen:

Source code : http://www.katewolfmuller.com/xx/sliding_win_test.fla

Thanks,
Johann