private void btnAssign_Click(object sender, RoutedEventArgs e) { if (lstEmployees.SelectedIndex == -1 || lstOrders.SelectedIndex == -1) { MessageBox.Show("Please select both an employee and an order", "Error"); } else { try { selectedEmployee = (UserModel)lstEmployees.SelectedItem; selectedOrder = (OrderModel)lstOrders.SelectedItem; OrderProcessor.AssignEmployeeToOrder(selectedEmployee.UserID, selectedOrder.OrderID, currentUser.Token); } catch (Exception ex) { MessageBox.Show(ex.Message); } } }