Customizing Your Own Version
To personalize your version of the tabbed interface, simply edit the contents of Page 1 through Page 3 and Page Set. To add more tabs, you can create more labeled key frames in the Page Set symbol. Duplicate one of the Page symbols in the Library, naming it Page 4 (5, 6, and so on), then position it in the main timeline like the original three.
As you add pages or just resize the three that already come with the example, don't forget to alter the PageX and PageY variables so that the pages are positioned correctly when being viewed. That's all there is to it.