Two level CSS Tabs menu

[moisea]

1) Script Title: Two level CSS Tabs menu

2) Script URL (on DD): http://www.dynamicdrive.com/style/cs...css-tabs-menu/

3) Describe problem:
hi, i need some help with the Two level CSS Tabs menu tutorial please.
i need to make it work so that it enables me to select any maintab and the submenu of that maintab to appear.
i don't also get how the Class selected works also. there must be a script missing here to make it work too.
any idea on how to do that please?

many thanks.