Adding a panel to a frame

Question

Hi! All,
I'm new to java and i have a little problem here. I have created a frame and i want to put two panels inside it. well, i managed to put the first one, but i'm having problems with the second one. I want this second one to be added when I click on a button.
The button that I will click is the new JButton i have defined. it is called draw. I really do not know what the problem is. I will apprecite any help. Below is my code.
// My Code.
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.net.*;
import java.util.*;
public class Main extends JFrame {
//all components I'll need
public JButton draw;
public JButton addFormula;
public JButton modelCheck;
/** Creates a new instance of Main */
public Main () {
super("Graphical Model Checker for Knowledge");
//content pane is the main panel where i'll put everything
JPanel contentPane = new JPanel();
draw = new JButton("Draw");
draw.addActionListener(
new ActionListener() {         
public void actionPerformed(ActionEvent event) {
if(event.getActionComman().equals"Draw")) {               
JPanel drawing = new JPanel();
drawing.setBackground(Color.BLUE);
drawing.setSize(100, 100);
drawing.setLayout(new FlowLayout
FlowLayout.CENTER));
add("North", drawing);
drawing.setVisible(true);
contentPane.add(draw);
addFormula = new JButton("Add Formula");
contentPane.add(addFormula);
modelCheck = new JButton("Model Check");
contentPane.add(modelCheck);
Canvas canvas = new Canvas();
canvas.setSize(40, 40);
canvas.setBackground(Color.white);
contentPane.add(canvas);
repaint();
//add panel to the frame
add("South", contentPane);
//colours for window
contentPane.setBackground(Color.yellow);
//set layout manager
contentPane.setLayout(new FlowLayout(FlowLayout.LEFT));
addWindowListener(new CloseWindow());
pack();
setVisible(true);
String [] fileItems = {"Open", "Save", "Rename"};
String [] editItems = {"Copy", "Cut", "Paste"};
//instantiate a menu bar object
JMenuBar bar = new JMenuBar();
JMenu file = new JMenu("File");
for (int index=0; index != fileItems.length; index++)
file.add(fileItems[index]);
bar.add(file);
setJMenuBar(bar);
JMenu edit = new JMenu("Edit Graph");
for (int index=0; index != editItems.length; index++)
edit.add(editItems[index]);
bar.add(edit);
setJMenuBar(bar);
public static void main(String args []) {
JFrame window = new Main();
}

Answer 1

Don't forget to use the "Code Formatting Tags",
see http://forum.java.sun.com/help.jspa?sec=formatting,
so the posted code retains its original formatting.
add("North", drawing); The "North" means nothing when adding a component to a panel using a FlowLayout. You should just be using:
add( drawing );After you add the component to the container you need to use:
frame.validate();