Adding Items and Removing Itesm from JList

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

    public class PhilosophersJList extends JFrame {
    
     private DefaultListModel philosophers;
     private JList list;
    
     public PhilosophersJList()
         {
         super( "Favorite Philosophers" );
        
         // create a DefaultListModel to store philosophers
         philosophers = new DefaultListModel();
         philosophers.addElement( "Socrates" );
         philosophers.addElement( "Plato" );
         philosophers.addElement( "Aristotle" );
         philosophers.addElement( "St. Thomas Aquinas" );
         philosophers.addElement( "Soren Kierkegaard" );
         philosophers.addElement( "Immanuel Kant" );
         philosophers.addElement( "Friedrich Nietzsche" );
         philosophers.addElement( "Hannah Arendt" );
        
         // create a JList for philosophers DefaultListModel
         list = new JList( philosophers );
        
         // allow user to select only one philosopher at a time
         list.setSelectionMode(
         ListSelectionModel.SINGLE_SELECTION );
        
         // create JButton for adding philosophers
         JButton addButton = new JButton( "Add Philosopher" );
         addButton.addActionListener(
             new ActionListener() {
            
             public void actionPerformed( ActionEvent event )
                 {
                 // prompt user for new philosopher's name
                 String name = JOptionPane.showInputDialog(
                 PhilosophersJList.this, "Enter Name" );
                
                 // add new philosopher to model
                 philosophers.addElement( name );
             }
         }
         );
        
         // create JButton for removing selected philosopher
         JButton removeButton =
         new JButton( "Remove Selected Philosopher" );
        
         removeButton.addActionListener(
             new ActionListener() {
            
             public void actionPerformed( ActionEvent event )
                 {
                 // remove selected philosopher from model
                 philosophers.removeElement(
                 list.getSelectedValue() );
             }
         }
         );
        
         // lay out GUI components
         JPanel inputPanel = new JPanel();
         inputPanel.add( addButton );
         inputPanel.add( removeButton );
        
         Container container = getContentPane();
         container.add( list, BorderLayout.CENTER );
         container.add( inputPanel, BorderLayout.NORTH );
        
         setDefaultCloseOperation( EXIT_ON_CLOSE );
         setSize( 400, 300 );
         setVisible( true );
        
     } // end PhilosophersJList constructor
    
     // execute application
     public static void main( String args[] )
         {
         new PhilosophersJList();
     }
}