import javax.swing.JFrame;
import javax.swing.JButton;
import java.awt.FlowLayout;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;

class Program01 extends JFrame implements ActionListener {
	JButton klikkGomb;
	
	Program01() {		
		klikkGomb = new JButton("Klikkelj ide");
		klikkGomb.addActionListenner(this);
		add(klikkGomb);
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		setSize(400, 300);		
	}
	public static void actionPerfomed(ActionEvent event) {
		setTitle("Működik");
	}
	public static void main(String[] args) {
		new Program01().setVisible(true);
	}
}