private void btnRemove_Click(object sender, RoutedEventArgs e)
        {
            ProductsOrderedDS ps = dgvProductsOrdered.SelectedItem as ProductsOrderedDS;

            if (ps != null)
            {
                lstProdDS.Remove(ps);
                dgvProductsOrdered.ItemsSource = lstProdDS;
                dgvProductsOrdered.Items.Refresh();
            }
        }
        private void button_Click(object sender, RoutedEventArgs e)
        {
            ProductsOrderedDS ps = new ProductsOrderedDS();
            Products          p  = cmbProducts.SelectedItem as Products;

            if (p != null)
            {
                ps.Products = p;
                ps.Price    = txtPrice.Text;
                ps.Qty      = txtQty.Text;
            }

            lstProdDS.Add(ps);
            dgvProductsOrdered.ItemsSource = lstProdDS;
            dgvProductsOrdered.Items.Refresh();
            ps = new ProductsOrderedDS();
            clearFields();
        }