In This version programer has to modify both html and css to get nested menu navigation. http://jsfiddle.net/gh/get/mootools/1.2/nabilr/w3programming/tree/master/menu_navigation
Ver1. Simlified the effort for a programmer. They have to just focus on html, from it builts the nested UI navigation.
http://jsfiddle.net/gh/get/mootools/1.2/nabilr/w3programming/tree/master/menu_navigation_ver1