BlueSky.Windows.AddFactorLevelsDialog.removelvlbutton_Click C# (CSharp) Method

        private void removelvlbutton_Click(object sender, RoutedEventArgs e)
        {
            string selectedlevel = levelsListBox.SelectedItem.ToString();
            if (FactorLevels.Contains(selectedlevel))
            {
                FactorLevels.Remove(selectedlevel);
                levelsListBox.ItemsSource = null;
                levelsListBox.ItemsSource = FactorLevels;
            }
            else
            {
                MessageBox.Show("Cannot Remove Level! ", "Remove Level", MessageBoxButton.OK, MessageBoxImage.Warning);
            }
        }