Javascript无刷新TreeView

<%@ Page Language="C#" %>
<%@ Import Namespace="System.IO" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">

    void Treeview1_TreeNodePopulate(object sender, TreeNodeEventArgs e)
    {
       if (IsCallback)
            if (e.Node.ChildNodes.Count == 0)
            {
                LoadChildNode(e.Node);
            }

    }

    private void LoadChildNode(TreeNode node)
    {

        DirectoryInfo directory;
        directory = new DirectoryInfo(node.Value);

        foreach (DirectoryInfo sub in directory.GetDirectories())
        {

            TreeNode subNode = new TreeNode(sub.Name);
            subNode.Value = sub.FullName;

            try
            {
                if (sub.GetDirectories().Length > 0 || sub.GetFiles().Length > 0)
                {
                    subNode.SelectAction = TreeNodeSelectAction.SelectExpand;
                    subNode.PopulateOnDemand = true;
                    subNode.NavigateUrl = "#";
                }
           }
            catch { subNode.ImageUrl = "WebResource.axd?a=s&r=TreeView_XP_Explorer_ParentNode.gif&t=632242003305625000"; }
            node.ChildNodes.Add(subNode);

        }

        foreach (FileInfo fi in directory.GetFiles())
        {
            TreeNode subNode = new TreeNode(fi.Name);
            node.ChildNodes.Add(subNode);
        }
    }


</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>Untitled Page</title>
</head>