Treeview Folders and Files VB

I'm trying to use the Treeview cvontrol for the first time. I found several sources on the web to help configure the treeview. The problem I have is with the Navigate URL. The example I have will not link to documents in the subfolders in the tree structure. Here is what I have for the Treeview control followed by the code behind page.  Any ideas what I can do to make the links work. Thanks-Rob
asp:treeview ID="Treeview1" runat="server" ImageSet="XPFileExplorer" AutoGenerateDataBindings="false" ExpandDepth=0 OnTreeNodePopulate="Treeview1_TreeNodePopulate" > <SelectedNodeStyle BackColor="#B5B5B5"></SelectedNodeStyle> <Nodes><asp:TreeNode Value="C:/Tip Sheets" Text="Tip Sheets" PopulateOnDemand="true" SelectAction="Select" NavigateUrl="#" > </asp:TreeNode> </Nodes> <NodeStyle V ...