@Override
 public void insertSalesOrder(SalesOrder so) {
   dao.insert(so);
 }
 @Override
 public SalesOrder getSalesOrder(Integer id) {
   return dao.getSalesOrder(id);
 }
 @Override
 public void updateSalesOrder(SalesOrder so) {
   dao.update(so);
 }
 @Override
 public void deleteSalesOrder(Integer id) {
   dao.delete(id);
 }
 @Override
 public List<SalesOrder> getAllSalesOrders() {
   return dao.getAllSalesOrders();
 }