Sub Menu

Refer here

http://www.aspsnippets.com/Articles/Simple-Hover-Menu-using-jQuery-and-JavaScript.aspx

Have you also tried searching for examples at google or  bing? I'm sure you'll get alot of examples out there. Here's one criteria: http://www.google.com.ph/#sclient=psy-ab&hl=tl&source=hp&q=css+submenu+example&pbx=1&oq=css+submen&aq=2&aqi=g4&aql=&gs_sm=e&gs_upl=0l0l1l315l0l0l0l0l0l0l0l0ll0l0&bav=on.2,or.r_gc.r_pw.,cf.osb&fp=ae603e9fb44908c&biw=1680&bih=946

<div id="navigation">
        <ul>
            <li>
            <a href="#">Menu Item 1</a>
                <ul>
 <li>sub menu item 1</li>
 <li>sub menu item 2</li>
 <li>sub menu item 3</li>
 <li>sub menu item 4</li>
 </ul>
            </li>

            <li>
            <a href="#">Menu Item 2</a>
                <ul>
 <li>sub menu item 1</li>
 <li>sub menu item 2</li>
 <li>sub menu item 3</li>
 <li>sub menu item 4</li>
 </ul> 
            </li>

            <li>
            <a href="#">Menu Item 3</a>
                <ul>
 <li>sub menu item 1</li>
 <li>sub menu item 2</li>
 <li>sub menu item 3</li>
 <li>sub menu item 4</li>
 </ul>
            </li>

            <li>
            <a href="#">Menu Item 4</a>
                <ul>
 <li>sub menu item 1</li>
 <li>sub menu item 2</li>
 <li>sub menu item 3</li>
 <li>sub menu item 4</li>
 </ul>
            </li>
        </ul>


    </div>

For more details please check out this link...

http://www.devinrolsen.com/pure-css-horizontal-menu/


It might be useful for you.