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

class HelloSwing5 extends JFrame implements ActionListener
{

    HelloSwing5()
    {
        setTitle("Hello Swing5");
        setLayout(new FlowLayout());
        setSize(400,300);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        Container c=getContentPane();
        JButton btn=new JButton("Click me!");
        c.add(btn);
        btn.addActionListener(this);

        setVisible(true);
    }

    public void actionPerformed(ActionEvent e)
    {
        int i=JOptionPane.showConfirmDialog(this,"Hello");
    }
}

public class Ex5
{
    public static void main(String[] args)
    {
        new HelloSwing5();
    }
}