ASP.NET

<%@ WebHandler Language="C#" Class="Handler" %>
        
using System;
using System.Web;
using System.Web.SessionState;
          
public class Handler : IHttpHandler, IRequiresSessionState  
{
    public void ProcessRequest (HttpContext context) {

        if (context.Session["SessionName"] == null)
            context.Session["SessionName"] = 0;
                                  
        int counter = (int)context.Session["SessionName"];
        counter++;
        context.Session["SessionName"] = counter;
                             
        context.Response.ContentType = "text/plain";
        context.Response.Write("Counter: " + context.Session["SessionName"]);
    }
        
    public bool IsReusable {
        get {
            return false;
        }
    }
}

   Sub SaveNodes(ByVal nodesCollection As TreeNodeCollection, ByVal textWriter As System.Xml.XmlTextWriter)
      Dim link_node As TreeNode
      For Each link_node In nodesCollection
         If link_node.ChildNodes.Count Then
            textWriter.WriteStartElement("Folder")
            textWriter.WriteAttributeString("Name", link_node.Text)
            textWriter.WriteRaw(vbCrLf)
         Else
            textWriter.WriteStartElement("Link")
            textWriter.WriteAttributeString("Name", link_node.Text)
            textWriter.WriteAttributeString("Location", link_node.NavigateUrl)
         End If

         If link_node.ChildNodes.Count > 0 Then
            SaveNodes(link_node.ChildNodes, textWriter)
         End If
         textWriter.WriteEndElement()
         textWriter.WriteRaw(vbCrLf)
      Next
   End Sub

   Sub SaveTreeViewData(ByVal treeView As TreeView, ByVal path As String)
      'Create a serializer and file to save TreeViewData
      Dim TextWriter As New System.Xml.XmlTextWriter(path, System.Text.Encoding.UTF8)

      TextWriter.WriteStartDocument()
      TextWriter.WriteRaw(vbCrLf)

      SaveNodes(treeView.Nodes, TextWriter)

      TextWriter.Close()
   End Sub


   Protected Sub Save_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Save.Click
      SaveTreeViewData(Link_Tree, "favorites.xml")
End Sub