protected void btnExport_Click(object sender, EventArgs e) { StoreFront ObjStoreFront = new StoreFront(); DataSet ds = new DataSet(); ds = ObjStoreFront.GetAllContactUsExport(Convert.ToDateTime(txtStartDate.Text.Trim()), Convert.ToDateTime(txtEndDate.Text.Trim())); if (ds.Tables[0].Rows.Count > 0) { DataTable dt = new DataTable(); dt = ds.Tables[0]; Response.ContentType = "Application/vnd.ms-msexcel"; Response.AddHeader("content-disposition", "attachment;filename=ContactUs.csv"); Response.Write(ToCSV(dt)); Response.End(); } else { ErrMessage("No record found"); } }