I have a simple app, showing picture made of tiled images(named u1, u2,...,u16.jpg). Now I'd like to add some Events to it, so that I can show these images only when proper button is clicked. I've tried doing it on my own, but it's not working. Where am I doing something wrong?

Original code :

import java.awt.GridLayout;
import javax.swing.*;
import javax.swing.border.BevelBorder;

public class Tiles_2 {

    public static void main(String[] args) {
        final JFrame f = new JFrame("Usmiech");
        JPanel panel = new JPanel(new GridLayout(4, 4, 3, 3));
        JLabel l = new JLabel();

        for (int i = 1; i < 17; i++) {
            String path = "u"+ i+".jpg";
            l = new JLabel(new ImageIcon(path));
            l.setBorder(BorderFactory.createBevelBorder(BevelBorder.RAISED));
            panel.add(l);
        }

        f.setContentPane(panel);
        f.setSize(300, 300);
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        f.setVisible(true);
    }
}

New code :

import java.awt.GridLayout;
import javax.swing.*;
import javax.swing.border.BevelBorder;
import java.awt.event.*;

public class Zad_8_1 implements ActionListener {

    public void actionPerformed(ActionEvent e) {
        JButton b = (JButton)(e.getSource());
        String i = b.getText();
        b = new JButton(new ImageIcon("u"+i+".jpg"));
    }

    public static void main(String[] args) {
        final JFrame f = new JFrame("Smile");
        JPanel panel = new JPanel(new GridLayout(4, 4, 3, 3));
        JButton l = null;

        for (int i = 1; i < 17; i++) {
            String path = "u"+ i+".jpg";
            l = new JButton(""+i);
            l.setBorder(BorderFactory.createBevelBorder(BevelBorder.RAISED));
            l.setSize(53,53);
            panel.add(l);
        }

        f.setContentPane(panel);
        f.setSize(300, 300);
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        f.setVisible(true);
    }
}

This should work like this : http://img535.imageshack.us/img535/3129/lab8a.jpg