public void DisplayBookingReport()
    {
        DataSet dsBook = objReport.DisplayBookingReport();

        if (dsBook.Tables[0].Rows.Count > 0)
        {
            Gvboooking.DataSource = dsBook.Tables[0];
            Gvboooking.DataBind();
        }
    }
 protected void btnPdf_Click(object sender, EventArgs e)
 {
     Response.Clear();
     Response.AddHeader("content-disposition", "attachment;filename=DocumentReport.pdf");
     Response.Charset = "";
     Response.Cache.SetCacheability(HttpCacheability.NoCache);
     Response.ContentType = "application/pdf";
     System.IO.StringWriter       stringWrite = new System.IO.StringWriter();
     System.Web.UI.HtmlTextWriter htmlWrite   = new HtmlTextWriter(stringWrite);
     Gvboooking.RenderControl(htmlWrite);
     Response.Write(stringWrite.ToString());
     Response.End();
 }