Project Seven SwapClass

Hello,

I completed and understand the project seven tutorial, SwapClass:
http://projectseven.com/tutorials/na...menu/index.htm

However, I'm trying to recreate the navigation menu for my own site and have a
few questions. First, the only defining characteristics I can find in the code
of their workpage.htm with regards to the ".open" and ".closed" classes are
that they either "display block" in the open class, or "display none" in the
closed class. Am I missing some aspect of defining these classes? Second,
they have their navigation menu as an unordered list in an absolutely placed
div. Will it make a difference if I try to create a working toggle menu like
this with my menu options defined as an unordered list within a table? I
finally have got my layout properly placed and would prefer not to work with
layers and divs if possible...

Thanks much for your input!