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

public class MyCombo extends JFrame{
	private JLabel showLabel;
	private JPanel messagePanel;
	String[] messages;
	JComboBox messageBox;

	public MyCombo()
	{
		messages = new String[3];
		messages[0] = "A message";
	   messages[1] = "Another message";
		messages[2] = "A creative message";
		messageBox = new JComboBox(messages);
		messageBox.setEditable(true);
		messageBox.addItemListener(new ItemListener() {
			public void itemStateChanged(ItemEvent event) {
				if (event.getStateChange() == ItemEvent.SELECTED)
				{
					if (messageBox.getSelectedIndex() == -1)
						messageBox.addItem(
							messageBox.getSelectedItem());
					showLabel.setText((String) 
							messageBox.getSelectedItem());
				}
			}
		} ); // end listener

		showLabel = new JLabel(messages[0]);
		messagePanel = new JPanel();
		messagePanel.add(messageBox);

		Container container = getContentPane();
		container.setLayout(new BorderLayout());
		
		container.add(showLabel, BorderLayout.NORTH);
		container.add(messagePanel, BorderLayout.CENTER);

		setSize(265,300);
		setVisible(true);
	}

	public static void main(String[] args)
	{
		MyCombo app = new MyCombo();
		app.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
	}			
}