Customizing Zii.widgets.cmenu

Hi


I have a menu with the following structure:

<div id="topmenu"> <ul id="nav">
			<li><a href="#">Resources</a>
				<ul>
					<li><a href="#">Premium</a>
						<ul>
							<li><a href="#">Software A</a></li>
							<li><a href="#">Software B</a></li>
							<li><a href="#">Software C</a></li>
							<li><a href="#">Software D</a></li>
													</ul>
					</li>
					<li><a href="#">Free </a>
						<ul>
							<li><a href="#">Trial Version Software A</a></li>
							<li><a href="#">Trial Version Software b</li>
						</ul>
					</li>
										
		
				</ul>
			</li>
		
			<li><a href="#">Contact</a>
				<ul>
					<li><a href="#">Press Release</a></li>
					<li><a href="#">Contact</a></li>
					
		
				</ul>
			</li>
		
			<li><a href="#">Members</a>
				<ul>
		
					<li><a href="#">Login</a></li>
					<li><a href="#">Register</a></li>

					
				</ul>
			</li>
		
		</ul>
</div>

The nested list is opens a submenu.
How do i customize the zii.widgets.CMenu to accomodate this ?

Any ideas or links would be really appreciated.

Thanks