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

public class AreaDialogs extends JFrame 
    implements ActionListener {

    private JButton button;

    public static void main(String[] args) {
        AreaDialogs frame = new AreaDialogs();
        frame.setSize(400, 300);
        frame.createGUI();
        frame.show();
    }

    private void createGUI() {
        setDefaultCloseOperation(EXIT_ON_CLOSE);
        Container window = getContentPane();
        window.setLayout(new FlowLayout() );

        button = new JButton("Press me");
        window.add(button);
        button.addActionListener(this);
    }

    public void actionPerformed(ActionEvent event) {
        int area;
        int length;
        int width;
        String lengthString;
        String widthString;

        lengthString = JOptionPane.showInputDialog("Length:");
        length = Integer.parseInt(lengthString);     
        widthString = JOptionPane.showInputDialog("Width:");
        width = Integer.parseInt(widthString);
        area = length * width;
        JOptionPane.showMessageDialog(null, "Area is: " + area);
    }
}