Exporting Dataset to excel

public void ExportDataSetToExcel(DataSet ds, string filename)
        {
            HttpResponse response = HttpContext.Current.Response;

            // first let's clean up the response.object   
            response.Clear();
            response.Charset = "";

            // set the response mime type for excel   
            response.ContentType = "application/vnd.ms-excel";
            response.AddHeader("Content-Disposition", "attachment;filename=\"" + filename + "\"");

            // create a string writer   
            using (StringWriter sw = new StringWriter())
            {
                using (HtmlTextWriter htw = new HtmlTextWriter(sw))
                {
                    // instantiate a datagrid   
                    DataGrid dg = new DataGrid();
                    dg.DataSource = ds.Tables[0];

                    dg.DataBind();
                    dg.RenderControl(htw);
                    response.Write(sw.ToString());
                    response.End();
                }
            }

        }