private void BTM_PRINT_BILL_Click(object sender, EventArgs e) { //get last order to print it int order_id = Convert.ToInt32(ORDER.GET_LAST_ORDER_ID_for_print().Rows[0][0]); RPT.RPT_ORDER REPORT = new RPT.RPT_ORDER(); RPT.FRM_RPT_PRODUCT FRM = new RPT.FRM_RPT_PRODUCT(); REPORT.SetDataSource(ORDER.GET_ORDER_DETAILS(Convert.ToInt32(order_id))); FRM.crystalReportViewer1.ReportSource = REPORT; FRM.ShowDialog(); }