Export Data table into ms Excel file in asp.net

private void FnExportDataIntoExcel()                   {                                        // get data from Database                                                    dtDataToExport = objDBClass.GetDataFunction(objParam);   // call Data access layer function to get data from Database to export                                                                     if (dtDataToExport != null                        && dtDataToExport.Rows.Count > 0)                 {                     DataTable dataTable = dtDataToExport;                     //File Name                     string DT = DateTime.Now.ToString("yyyyMMdd_hhmmsssstt");                     // Set up the Response object...                     this.Response.BufferOutput = false;                     this.Response.Charset = string.Empty;                     this.Response.Clear();                     this.Response.ClearContent();                     this.Response.ClearHeaders();                     this.Response.ContentType = "application/vnd.ms-excel";                     // Open the document OVER this window:                     string contentDisposition = "attachment; filename=" + "SalesReport_GST" + "_" + DT + ".xls";                     this.Response.AppendHeader("content-disposition", contentDisposition);                     // Create a table HTML tag...                     string textOutput =                     "<table border='1' bordercolor='black' rules='all' " +                     "style='BORDER: 1px double; BORDER-COLLAPSE: collapse;'>\r\n";                     this.Response.Write(textOutput);                     // Write out the column headers...                     textOutput = "<tr height=17 style='height:12.75pt'>\r\n";                     for (int i = 0; i < dataTable.Columns.Count; i++)                     {                         textOutput += string.Format(                         System.Globalization.CultureInfo.InvariantCulture,                         "<th align='left'>{0}</th>",                         dataTable.Columns[i].ColumnName);                     }                     textOutput += "</tr>\r\n";                     this.Response.Write(textOutput);                     // Write out each row of the DataTable...                     textOutput = string.Empty;                     for (int i = 0; i < dataTable.Rows.Count; i++)                     {                         System.Data.DataRow dataRow = dataTable.Rows[i];                         textOutput = "<tr height=17 style='height:12.75pt'>\r\n";                         // Loop through the columns for each row and grab the values...                         for (int j = 0; j < dataTable.Columns.Count; j++)                         {                             string dataRowText = dataRow[j].ToString().Trim();                             // Remove any tabs, carriage returns, or newlines from the value...                             dataRowText = dataRowText.Replace("\t", " ");                             dataRowText = dataRowText.Replace("\r", string.Empty);                             dataRowText = dataRowText.Replace("\n", " ");                             textOutput += string.Format(                             System.Globalization.CultureInfo.InvariantCulture,                             "<td align='left' style='mso-number-format:\\@;'>{0}</td>",                             dataRowText);                         }                         textOutput += "</tr>\r\n";                         this.Response.Write(textOutput);                     }                     // Close the HTML table tag...                      textOutput = "</table>\r\n";                     this.Response.Write(textOutput);                     // Close the Response stream...                     this.Response.Flush();                     this.Response.Close();                     //  this.Response.End();;                     HttpContext.Current.Response.Flush();                     HttpContext.Current.Response.SuppressContent = true;                     HttpContext.Current.ApplicationInstance.CompleteRequest();                 }                 else                 {                                                                                                                                                                 // call your function to show message like this                      string  msg = "No Records Found to export";                     // bgcolor = "red";                     //DisplayMessage(msg, bgcolor);                 }                                 }