Creating Sub Menu's in asp.net?

[a_jonetkal]

HI,
I have already created a side and top bar menu but now i want to add sub menu's to it. It should scroll down and show the sub menu. I am pasting my code. See if any one can please help.
ul#menu
{
padding: 0 0 20px;
position: absolute;
margin: 0;
text-align: right;
float:right;
clear:both;
font-size:1.2em;
}
ul#menu li
{
display: inline;
list-style: none;
width:100px;
}
ul#menu li#greeting
{
padding: 5px 10px;
font-weight: bold;
text-decoration: none;
line-height: 1em;
color: #fff;
}
ul#menu li a
{
padding: 5px 10px;
font-weight: bold;
text-decoration: none;
line-height: 1em;
background-color: #e8eef4;
color: #034af3;
}
ul#menu li a:hover
{
background-color: #fff;
text-decoration: none;
}

ul#menu li a:active
{
background-color: #a6e2a6;
text-decoration: none;
}

ul#menu li.selected a
{
background-color: #fff;
color: #000;
}

#menucontainer
{
margin: 0;
padding:0;
}
and then i have 2 user controls code for which is
<%@ Control Language="VB" ClassName="WebUserControl1"%>

<ul id="menu" >


<<li><a href="../default.aspx">Home</a></li>

<li><a href="../Conference/Conference.aspx">Conferenece</a></li>

<li><a href="../Registrations/Registrations.aspx">Register</a></li>

<li><a href="../Events/Events.aspx">Events</a></li>

<li><a href="../News/News.aspx" >News</a></li>

<li><a href="../ContactUs/ContactUs.aspx" >Contact Us</a></li>

</ul>

Thanks in advance