onclick and close or invisible for some link

Hi all, I have some tree menu can I  hidden the submen ( I click one , every link under one   get show, untill I click two , every links under two show)<ul id="treemenu1" class="treeview">
<li>
<b>what is Matters</b>
<li>
<asp:linkbutton id="lbEntVisaApp" runat="server">One </asp:linkbutton>
<ul>
<li>
<asp:linkbutton id= ...