Guidelines are creating a cardlayout with 3 cards: login, fred and bob. import java.awt.event.*; import javax.swing.*; import java.awt.*; import javax.swing.JButton; import javax.swing.JFrame; import...

Guidelines are creating a cardlayout with 3 cards: login, fred and bob.

import java.awt.event.*;
import javax.swing.*;
import java.awt.*;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import java.awt.BorderLayout;
import java.awt.CardLayout;
import java.awt.FlowLayout;
import java.awt.Color;
import java.awt.Container;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

public class SimpleCardWindow extends JFrame implements ActionListener {
public static final int WIDTH = 300;
public static final int HEIGHT = 300;

private CardLayout theCardsLayoutManager;
private JPanel theCardsPanel;
private JTextField userTextField;
private JTextField passwordTextField;
private JButton loginButton;
private JButton bobWordButton;
private JTextField bobEntryTextField;
private JTextArea bobDisplayTextArea;
private JButton bobReturnButton;
private JPanel fredCard;
private JPanel fredButtonPanel;
private JButton fredRedColorButton;
private JButton fredGreenColorButton;
private JButton fredReturnButton;

public SimpleCardWindow() {
super();
setSize(WIDTH, HEIGHT);
setTitle("CardLayout Demonstration");
theCardsPanel = new JPanel();
theCardsLayoutManager = new CardLayout();
theCardsPanel.setLayout(theCardsLayoutManger);

//login card//
JPanel loginCard = new JPanel();
loginCard.setLayout(new GridLayout(3,1));
userTextField = new JTextField("Username:");
passwordTextField = new JTextField("Password:");

loginButton = new JButton("Login");
loginButton.addActionListener(this);
loginCard.add(userTextField);
loginCard.add(passwordTextField);
loginCard.add(loginButton);
theCardsPanel.add("loginCard",loginCard);

//bob card//
JPanel bobCard = new JPanel();
bobCard.setLayout(new BorderLayout());
bobWordButton = new JButton("Button 1");
bobWordButton.addActionListener(this);
bobEntryTextField = new JTextField("Button 2");
bobDisplayTextArea = new JTextArea(5, 20);
bobDisplayTextArea.setEditable(false);
bobReturnButton = new JButton("Return");
bobReturnButton.addActionListener(this);
JPanel bobEntryPanel = new JPanel();

bobEntryPanel.setLayout(new GridLayout(1,2));
bobEntryPanel.add(bobEntryTextField);
bobEntryPanel.add(bobWordButton);
bobCard.add(bobEntryPanel, BorderLayout.NORTH);
bobCard.add(bobDisplayTextArea, BorderLayout.CENTER);
bobCard.add(bobReturnButton, BorderLayout.SOUTH);
theCardsPanel.add("bobCard", bobCard);

//fred card//
fredCard = new JPanel();
fredCard.setLayout(new BorderLayout());
fredRedColorButton = new JButton("Button 1");
fredRedColorButton.addActionListener(this);
fredGreenColorButton = new JButton("Button 2");
fredGreenColorButton.addActionListener(this);
fredReturnButton = new JButton("Button 3");
fredReturnButton.addActionListener(this);
fredButtonPanel = new JPanel();
fredButtonPanel.add(fredGreenColorButton);
fredButtonPanel.add(fredRedColorButton);
fredCard.add(fredButtonPanel, BorderLayout.CENTER);
fredCard.add(fredReturnButton, BorderLayout.SOUTH);
theCardsPanel.add("fredCard", fredCard);
getContentPane().add(theCardsPanel, BorderLayout.CENTER);

//setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
WindowDestroyer listener = new WindowDestroyer();
addWindowListener(listener);
}

public void actionPerformed(ActionEvent e) {
if (e.getActionCommand().equals("Login")) {
String id = userTextField.getText();
String pass = passwordTextField.getText();

if (id.equals("Bob") && pass.equals("mubby"))
theCardsLayoutManager.show(theCardsPanel, "bobCard");

else if (id.equals("Fred") && pass.equals("goolag"))
theCardsLayoutManager.show(theCardsPanel, "fredCard");
}
else if (e.getActionCommand().equals("Return")) {
theCardsLayoutManager.show(theCardsPanel, "loginCard");
}

else if (e.getSource() == bobWordButton) {
String add = bobEntryTextField.getText();
System.out.println("word is " + add);
bobDisplayTextArea.append(add + "\n");
}

else if (e.getSource() == fredGreenColorButton) {
fredButtonPanel.setBackground(Color.GREEN);
}

else if (e.getSource() == fredRedColorButton) {
fredButtonPanel.setBackground(Color.RED);
}

else
System.out.println("Error in button interface.");
}

}

I'm receiving this error code:

1) SimpleCardWindow.java:42: error: cannot find symbol

theCardsPanel.setLayout(theCardsLayoutManger);
^

symbol: variable theCardsLayoutManger

location: class SimpleCardWindow

2) SimpleCardWindow.java:95: error: cannot find symbol

WindowDestroyer listener = new WindowDestroyer();
^

symbol: class WindowDestroyer

location: class SimpleCardWindow

3) SimpleCardWindow.java:95: error: cannot find symbol

WindowDestroyer listener = new WindowDestroyer();
^

symbol: class WindowDestroyer

location: class SimpleCardWindow