Completed Code ( 1 - 3 )

package testing;

import java.awt.Color;
import java.awt.Font;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.JButton;
import javax.swing.JCheckBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JTextField;

public class WindowTesting {

    public static JFrame frame;
    public static JButton button;
    public static JTextField textField;
    public static JCheckBox checkBox;
    public static JLabel label;

    public static void main(String[] args) {

        frame = new JFrame("A new window! :D");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setSize(640, 480);
        frame.setLayout(null);

        button = new JButton("BUTTON");
        button.setBounds(20, 20, 200, 100);
        button.addActionListener(new ActionListener() {

            @Override
            public void actionPerformed(ActionEvent e) {
                label.setText(textField.getText());
            }

        });

        textField = new JTextField();
        textField.setBounds(20, 140, 200, 40);

        checkBox = new JCheckBox("Checkbox");
        checkBox.setBounds(20, 180, 200, 40);
        checkBox.addActionListener(new ActionListener() {

            @Override
            public void actionPerformed(ActionEvent e) {

                if(checkBox.isSelected()){
                    button.setBackground(Color.RED);
                } else {
                    button.setBackground(null);
                }

            }
        });

        label = new JLabel("Hello World!!!");
        label.setBounds(20, 220, 200, 40);
        label.setFont(new Font("Comic Sans MS", Font.BOLD, 16));

        frame.add(button);
        frame.add(textField);
        frame.add(checkBox);
        frame.add(label);

        frame.setVisible(true);

    }

}