or
private void WriteToExcel(IReportDocument report)
{
ReportProcessor reportProcessor = new ReportProcessor();
RenderingResult result = reportProcessor.RenderReport("xls", report, null);
Response.Clear();
Response.ContentType = result.MimeType;
Response.Cache.SetCacheability(HttpCacheability.Private);
Response.Expires = -1;
Response.Buffer = true;
Response.AddHeader("Content-Disposition",
string.Format("attachment;FileName=\"{0}.xls\"", result.DocumentName));
Response.BinaryWrite(result.DocumentBytes);
Response.End();
}