private void ButtonEditOrder_Click(object sender, RoutedEventArgs e) { invoiceRepository.DisplayInvoiceFromOrder(order.OrderID); if (invoiceRepository.DisplayInvoiceFromOrder(order.OrderID) == true) { WindowShowDialog wsd = new WindowShowDialog(); wsd.LabelShowDialog.Content = "Der er allerede dannet en faktura på denne ordre!"; wsd.ShowDialog(); } else if (order != null) { WindowEditOrder weo = new WindowEditOrder(order); weo.ShowDialog(); Update(); } else { WindowShowDialog wsd = new WindowShowDialog(); wsd.LabelShowDialog.Content = "Ingen ordre er valgt!"; wsd.ShowDialog(); } }