Add Icon to a JCheckBox in Java

import java.awt.FlowLayout;
/* w ww.ja  va2 s  .com*/
import javax.swing.Icon;
import javax.swing.ImageIcon;
import javax.swing.JCheckBox;
import javax.swing.JFrame;

public class Main {

  public static void main(String[] args) {

    JFrame frame = new JFrame("JCheckBox Test");
    frame.setLayout(new FlowLayout());
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    JCheckBox ac = new JCheckBox("A/C");

    Icon rollIcon = new ImageIcon("a.gif");
    ac.setRolloverIcon(rollIcon);
    
    
    frame.add(ac);
    frame.pack();
    frame.setVisible(true);
  }
}