Add & update JLabels

Question

Hello guys,
My problem is: I got a JLabel with an image that is showed in the panel when I start the application. Then if the user clicks on a button, the JLabel must be replaced by another one.
I know about Event Handling, as you can see below. I'm confused about what JPanel Methods I should use to print on screen the new JPanel.
Heres a sample of my code (this file is not the main one..it is involked by another one):
import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
import java.util.*;
public class Simples extends JFrame implements ActionListener
public JFrame frame = new JFrame();
public JButton cg = new JButton();
public Simples()
     //Panel and JLabel
     final JPanel panel = new JPanel();
     final JLabel label1 = new JLabel ("LABEL_BEFORE_CLICKS);
pane.add(label1);
//JButton
JButton start = new JButton ("Start");
frame.getContentPane().add(panel, BorderLayout.CENTER);
     frame.pack();
frame.setVisible(true);
//events
     start.addActionListener(
     new ActionListener()
{      public void actionPerformed(ActionEvent e)
     { cg = (JButton)e.getSource();
JLabel label1 = new JLabel ("LABEL AFTER CLICKS");
panel.add(label1);
panel.remove(label1); /* IS THIS WRONG? WHAT SHOUD I DO HERE TO GET THE NEW LABEL DISPLAYED OVER THE OLD ONE?*/
frame.pack();
frame.repaint();

Answer 1

When you are changing a label don't worry about adding a new label in it's place just change the label that is already there with it's setText and setIcon methods. That way you don't have to remove and then add a new JLabel with is redundant anyway.