public void modifyService(object sender, RoutedEventArgs arg) { if (ServicesList.SelectedItem == null) { MessageBox.Show("Please select Service to change"); return; } if (ModifyService.Text == "") { MessageBox.Show("Cannot add blank name"); return; } ClientRequests.modifyService((String)ServicesList.SelectedItem, ModifyService.Text); filter = ClientRequests.getFilters(); ServicesList.ItemsSource = filter.services.Select(x => x.name); }