I have a
Confirm-user.aspx
<div id="sidebar">
<ul>
<li>
<h2>title</h2>
<ul>
<% foreach (DAL.Page page in pageList)
{%>
<% Response.Write("<li><a href="+page.PageAddress+">"+page.PageName+"</a></li>"); %>
<% }%>
</ul>
</li>
</ul>
</div>
http://localhost:2112/Manage_pages/ConfirmUser.aspx
http://localhost:2112/Manage_pages/Manage_pages/ConfirmUser.aspx
use
<a href='<%=ResolveClientUrl("~/ConfirmUser.aspx")%>'>text</a>
the "~/ConfirmUser.aspx"
could be "~/Manage_pages/ConfirmUser.aspx"
if Manage_pages
is your intended sub folder but not your application name