<asp:TemplateColumn HeaderText="No">           <HeaderStyle Font-Bold="True" Width="1%"></HeaderStyle>
......
<asp:TemplateColumn HeaderText="No">           <HeaderStyle Font-Bold="True" Width="20%"></HeaderStyle>
...........
<asp:TemplateColumn HeaderText="No">           <HeaderStyle Font-Bold="True" Width="20%"></HeaderStyle>
......
......

 private void btnExportToDoc_Click(object sender, System.EventArgs e)
 {
  string strTime = DateTime.Now.ToUniversalTime().ToString()+"_"+DateTime.Now.Millisecond.ToString();
  strTime = strTime.Replace("/", "_");
  strTime = strTime.Replace(":", "_");
  strTime = strTime.Replace(" ", "_");
 
  Response.Clear();
  Response.Buffer = true;
  Response.AddHeader("content-disposition", "attachment; filename=FileDoc_"+strTime+".xls");
  Response.ContentType = "application/vnd.ms-excel";
  Response.Charset = "";
  this.EnableViewState = false;
       
  System.IO.StringWriter oStringWriter = new System.IO.StringWriter();
  System.Web.UI.HtmlTextWriter oHtmlTextWriter = new System.Web.UI.HtmlTextWriter(oStringWriter);
 
  // Get the HTML for the control.
  dgProdReleaseValid.RenderControl(oHtmlTextWriter);
  // Write the HTML back to the browser.
  Response.Write(oStringWriter.ToString());

  Response.End();  
 }

private void btnExportToDoc_Click(object sender, System.EventArgs e)
{
...
...
		// Remove unneccessary controls of the Datagrid.
		RemoveDatagridControls(dgProdReleaseValid);
				
		// Output the DataGrid control content to the HTML TextWriter.
		dgProdReleaseValid.RenderControl(oHtmlTextWriter);
...
...
}

		/// <remarks>
		/// Note
		/// -----
		/// This is used to override void VerifyRenderingInServerForm to 
		/// avoid the below error when "Export to Doc" is clicked
		/// as this is a bug reported by MS.
		/// http://lab.msdn.microsoft.com/ProductFeedback/viewFeedback.aspx?feedbackid=e4e08db1-8788-4e58-9e1f-daba86195d9f
		///
		/// The error message looks like:
		/// Server Error in '/PPS' Application. 
		/// --------------------------------------------------------------------------------
		/// Control 'dgProdReleaseValid__ctl2_chkRelease' of type 'CheckBox' must be placed inside a form tag with runat=server. 
		/// Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code. 		
		///
		/// References:
		/// GridView Export to Excel Problems
		/// http://geekswithblogs.net/azamsharp/archive/2005/07/25/48213.aspx
		/// </remarks>
		public override void VerifyRenderingInServerForm(Control control)
		{
			// Confirms that an HtmlForm control is rendered 
			// for the specified ASP.NET server control at run time.
			
			// No code is required here.
		}
		
		/// <summary>
		/// Gets the custom date time format as a part of the filename.
		/// </summary>
		/// <remarks>
		/// References:
		/// - String Formatting in C#
		/// http://blog.stevex.net/index.php/string-formatting-in-csharp/					
		/// <summary>
		/// Removes unneccessary controls of a DataGrid.
		/// </summary>
		/// <remarks>
		/// References:
		/// - Extensive Study of GridView Export to Excel (Used by this method)
		/// http://www.gridviewguy.com/ArticleDetails.aspx?articleID=197
		/// - Export ASP.NET DataGrid to Excel
		/// http://www.c-sharpcorner.com/Code/2003/Sept/ExportASPNetDataGridToExcel.asp
		/// </remarks>
		private void RemoveDatagridControls(Control dg)
		{
			LinkButton lb = new LinkButton();
			Literal lit = new Literal(); 
			int i;
			
			for (i = 0; i < dg.Controls.Count; i++)
			{
				// If LinkButton type is found, remove it.
				if (dg.Controls[i].GetType() == typeof(LinkButton))
				{
					if (dg.Controls[i].Visible)
					{
						lit.Text = (dg.Controls[i] as LinkButton).Text; 
						dg.Controls.Remove(dg.Controls[i]);
						dg.Controls.AddAt(i, lit);
					} // End if.
				}
				// If DropDownList type is found, remove it.
				else if (dg.Controls[i].GetType() == typeof(DropDownList))
				{
					lit.Text = (dg.Controls[i] as DropDownList).SelectedItem.Text;
					dg.Controls.Remove(dg.Controls[i]);
					dg.Controls.AddAt(i, lit);
				}  // End if.

				if (dg.Controls[i].HasControls())
				{
					RemoveDatagridControls(dg.Controls[i]); 
				} // End if.
			} // End for.
		}