Why would you use javascript for a menu? Unless you are talking a .htc for IE6/lower, uhm... That's CSS' job. Do you have an example of what you want IN the menu?!? Kinda hard to code you a menu without knowing what's going in it... Well, not for the HTML... The html should just be something like: <ul id="menu"> <li><a href="/">Home</a></li> <li> <a href="/categories">Categories</a> <ul> <li><a href="/cars">Cars</a></li> <li><a href="/music">Music</a></li> <li><a href="/sports">Sports</a></li> </ul> </li> <li><a href="/links">Links</li> <li><a href="/contactUs">Contact Us</li> </ul> Code (markup): (assuming you want a drop-down/fly-out menu since that's the only reason you'd be asking for scripting in the first place)... As to how to make it drop-down/fly-out, the question becomes how do you want it styled and what direction? You're really not giving us enough to provide that. Though this assumes you want to build a website -- mentioning ASP.NET isn't exactly encouraging on that front given how badly it mangles HTML and pisses all over websites unless you give it a good swift kick in the crotch and micromanage the code.
All scripts including ASP generate pages by outputing HTML. So you can include JavaScript as you wish. There are various JS menus you can implement: http://www.queness.com/post/237/30-javascript-menu-plugins-and-scripts http://sixrevisions.com/javascript/20-excellent-javascript-navigation-techniques-and-examples/