TreeView loading from database... Error

Question

Hello:
 
I found this cool code...(IF, I get it to work) that loads the TreeView from a database. I found other code, but they only do two levels, I need multiple levels.
 
However, it seems that it uses some 'using System.Web.UI' if I include this in my program, I get a bunch of other error.
I am trying to get rig of and error  with the following line:
public void TreeViewICEPack_TreeNodePopulate(object sender, TreeNodeEventArgs e)
 
Can someone help?