Semantic and accessible DHTML multi-level menu

The purpose of this menu is to provide a semantic version of what is traditionally accomplished with tables. It uses nested UL lists and uses a PHP class to build the menu elements. These lists are displayed with CSS to create a nice customisable menu and nested lists are collapsed and expanded using javascript. If Javascript is disabled, the menu will display in expanded form. A second PHP class is supplied that traverses the file system and builds a menu, and two examples are provided along with sample CSS so you can see how to use the two classes.