The menu page is running in the left hand frame. As the mouse pointer moves over items in the menu (including its heading), the items turn red, then revert to their original colours when the pointer moves away.
When you click on a section header (News, Reviews, Tutorials), its content details are displayed, moving other headers down the screen to make room for it. Clicking a section header also loads a section introduction page into this frame (if you don't want this to happen, remove the code window.parent.Mainframe.navigate('HT1.htm'); from the onClick event handler of each menu header SPAN). Clicking on a header closes any other currently-open section, so you only have one section open at a time.
Note that in this demonstration system only the hyperlinks in the 'news' section are all active - this is deliberate!
Clicking on the menu header ('My Menu') will load this page back into the right-hand frame.