Edgar,
I would sue a slightly differnet approach. I would have three pages and disable page 3 when there were no notes, enable it when there are notes. Thsi way the user does not magically three pages sometimes and tow other times (which can be confusing if the user doesn;t understand when there are three and when there are two).
That said, the methods you need to use for your desired effect are of the PageFrame. You need the AddObject to add a page and the RemoveObject to remove the page. These are documented in the help file.