Treeview Control Problem

[Manick]

I have a treeview control in which i am reading the data from the database.I am populating the child nodes in the OnSelectedNodeChanged Event.I am getting all the child nodes in the root but i am unable to bind the root to the tree.

Can anyone point out mistake or addition to my code.

protected void TreeView1_SelectedNodeChanged(object sender, EventArgs e)
    {
               TreeNode root = TreeView1.SelectedNode;
        SqlConnection SqlCon = new SqlConnection("xyz");
        SqlCon.Open();
        SqlCommand Module_SqlCmd = new SqlCommand("xyz");
        SqlDataReader Module_Sdr = Module_SqlCmd.ExecuteReader();
 
        while (Module_Sdr.Read())
        {
            // Add children module to the root node
            TreeNode child = new TreeNode();
            //TreeNode root = TreeView1.SelectedNode;
            child.Text = Module_Sdr.GetValue(Module_Sdr.GetOrdinal("abc")).ToString();
            child.Target = "_blank";
            child.NavigateUrl = "your_page_Url.aspx";
            root.ChildNodes.Add(child);
 
        }
        Module_Sdr.Close();
        TreeNode tn=TreeView1.FindNode(TreeView1.SelectedNode.ValuePath);
        TreeView1.Nodes.Add(tn);
 
    }