private void AddPrintData(string no_penjualan)
        {
            StrukDataset.PenjualanRow penjualanRow = penjualans.NewPenjualanRow();
            penjualanRow.no_penjualan  = no_penjualan;
            penjualanRow.nama_kasir    = txtKasir.Text;
            penjualanRow.tgl_beli      = DateTime.Now;
            penjualanRow.nama_member   = txtNamaMember.Text;
            penjualanRow.total_harga   = lblSubtotal.Content.ToString();
            penjualanRow.total_item    = lblJumlahBarang.Content.ToString();
            penjualanRow.total         = lblTotalPembayaran.Text;
            penjualanRow.poin_terpakai = Convert.ToInt32(txtPoin.Text);
            penjualanRow.tunai         = Kenko.formatCurrency(double.Parse(Kenko.getNumber2(txtBayar.Text)));
            penjualanRow.kembalian     = lblKembalian.Content.ToString();

            penjualans.AddPenjualanRow(penjualanRow);

            foreach (DataRow row in dtPenjualan.Rows)
            {
                double harga = double.Parse(Kenko.getNumber(row["harga"].ToString()));
                StrukDataset.Detail_PenjualanRow detail_PenjualanRow = detail_Penjualans.NewDetail_PenjualanRow();
                detail_PenjualanRow.nama_obat = row["nama_obat"].ToString();
                detail_PenjualanRow.jumlah    = row["jumlah"].ToString();
                detail_PenjualanRow.harga     = Kenko.formatCurrency(harga);
                detail_Penjualans.AddDetail_PenjualanRow(detail_PenjualanRow);
            }
        }
        private void txtBayar_KeyDown(object sender, KeyEventArgs e)
        {
            if (e.Key == Key.Enter)
            {
                double totalPembayaran = Convert.ToDouble(Kenko.getNumber(lblTotalPembayaran.Text));
                double bayar           = double.Parse(Kenko.getNumber2(txtBayar.Text));
                if (bayar < totalPembayaran)
                {
                    MessageBox.Show("Uang pembayaran tidak mencukupi", "Gagal", MessageBoxButton.OK, MessageBoxImage.Error);
                }
                else
                {
                    double kembalian = double.Parse(Kenko.getNumber2(txtBayar.Text)) - totalPembayaran;
                    lblKembalian.Content = Kenko.formatCurrency(kembalian);

                    btnBayar.IsEnabled = true;
                }
            }
        }