jsp ul list element dynamic selection

[IamCool]

here is the situation:i have a nested ul list in my navigation bar ie \[code\]<li><ul><li> Some link</li></ul></li></ul>\[/code\]this is the navigation bar on left of my tiles and in right there is content related to it.so i want a particular li(main not nested) to be opened whenever i select a nested li.how to do it , by any way css or javascript.PS: i am a noob web developer so please suggest easy solutions and there is a possibility that this question have been asked before but i cant find an easy answer, so please don't rate it low.thanks