private void Bt_Add_Click(object sender, RoutedEventArgs e)
        {
            //Перевірка на нуль
            if (OrderDTO == null)
            {
                OrderDTO = new OrderDTO();
            }

            //Перевіряємо чи всі поля заповнені
            if (addNew)
            {
                if (String.IsNullOrWhiteSpace(tb_Date.Text) || String.IsNullOrWhiteSpace(tb_Count.Text) || cb_Client.SelectedIndex == -1 || cb_Address.SelectedIndex == -1 /*|| cb_Product.SelectedIndex==-1*/)
                {
                    return;
                }

                OrderDTO.Date  = DateTime.Parse(tb_Date.Text);
                OrderDTO.Count = Int32.Parse(tb_Count.Text);

                OrderDTO.Address = (cb_Address.SelectedValue as Address).Country;
                OrderDTO.Client  = (cb_Client.SelectedValue as ClientDTO).NameClient;
            }
            // string product = (cb_Product.SelectedValue as ProductDTO).NameProduct;// cb_Product.SelectedItem.ToString();

            UpdateOrders(service);

            this.DialogResult = true;

            service.AddOrder(OrderDTO);
        }