you may superfish jQuery plugin.
http://users.tpg.com.au/j_birch/plugins/superfish/
The menu structure should be in a standard ul li a structure
example
<ul class='menu'>
<li><a href="#">Company</a>
<ul>
<li><a href="#">Team</a></li>
<li><a href="#">Contact</a></li>
<li><a href="#">Something</a></li>
</ul>
</li>
<li><a href="#">Contact</a></li>
</ul>
Styling needs to be done for ul.menu and superfish should be added to script and can be activated by
$(document).ready(function() {
$('ul.menu').superfish();
});