ASP.NET Expand/Contract DataGrid

using System;
using System.Collections;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Web;
using System.Web.SessionState;
// ---------------------------------------------------------
// Tony Truong's ExpandGridSample
// Copyright (C) 2004 
// For further reference see http://www.codeproject.com
// ---------------------------------------------------------

using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.HtmlControls;
using Gorth.ExDataGrids;

namespace ExpandGridSample
{
	/// <summary>
	/// Summary description for WebForm1.
	/// </summary>
	public class WebForm1 : System.Web.UI.Page
	{
		protected Gorth.ExDataGrids.ExDataGrid DataGridReport1;
	
		private void Page_Load(object sender, System.EventArgs e)
		{
			if(!IsPostBack)
			{
				// Put user code to initialize the page here
				DataSet ds = new DataSet();
				ds.ReadXml(AppDomain.CurrentDomain.BaseDirectory + @"\Testdata.xml");

				Session["ExDataGridDemo"] = ds.Tables[0];

				DataGridReport1.DataSource = ds.Tables[0];
				DataGridReport1.DataBind();
			}
		}

		#region Web Form Designer generated code
		override protected void OnInit(EventArgs e)
		{
			//
			// CODEGEN: This call is required by the ASP.NET Web Form Designer.
			//
			InitializeComponent();
			base.OnInit(e);
		}
		
		/// <summary>
		/// Required method for Designer support - do not modify
		/// the contents of this method with the code editor.
		/// </summary>
		private void InitializeComponent()
		{    
			this.DataGridReport1.SortCommand += new System.Web.UI.WebControls.DataGridSortCommandEventHandler(this.OnSort);
			this.Load += new System.EventHandler(this.Page_Load);

		}
		#endregion

		private void OnSort(object source, System.Web.UI.WebControls.DataGridSortCommandEventArgs e)
		{
			DataTable aDT = (DataTable) Session["ExDataGridDemo"];

			DataGridReport1 = (ExDataGrid) source;
			string sNewSortExpression = e.SortExpression.ToString();
			DataView dv = aDT.DefaultView;
			dv.Sort = sNewSortExpression;

			DataGridReport1.DataSource=aDT;
			DataGridReport1.DataBind();
		}
	}
}