asp.net code for treeview

TreeViewItem Treeviewitem = (TreeViewItem)sender;
            if (Treeviewitem.Items.Count == 1 && Treeviewitem.Items[0] == dummyNode)
            {
                Treeviewitem.Items.Clear();
                try
                {
                    foreach (string s in Directory.GetDirectories(Treeviewitem.Tag.ToString()))
                    {                       
                        TreeViewItem Treeviewsubitem = new TreeViewItem();
                        Treeviewsubitem.Header = s.Substring(s.LastIndexOf("\\") + 1);
                        Treeviewsubitem.Tag = s;
                        Treeviewsubitem.FontWeight = FontWeights.Normal;
                        Treeviewsubitem.Items.Add(dummyNode);
                        Treeviewsubitem.Expanded += new RoutedEventHandler(folder_Expanded);
                        Treeviewitem.Items.Add(Treeviewsubitem);
                    }
                }
                catch (Exception) { }
            }

<asp:TreeView ID="TreeView1" runat="server">
         <Nodes>
             <asp:TreeNode Text="Hosting Service" Value="Hosting Service">
                 <asp:TreeNode ImageUrl="~/images/customer1.png" Text="Customers"
                     Value="Customers"></asp:TreeNode>
                 <asp:TreeNode Text="Employees" Value="Employees"></asp:TreeNode>
                 <asp:TreeNode Text="Domain" Value="Domain"></asp:TreeNode>
                 <asp:TreeNode Text="Subscription" Value="Subscription"></asp:TreeNode>
                 <asp:TreeNode Text="Service Plan" Value="Service Plan"></asp:TreeNode>
             </asp:TreeNode>
         </Nodes>
     </asp:TreeView>