JLayeredPane possible in BorderLayout.CENTER ?

hi,
I tried to use JLayeredPane as follows and nothing in it shows up.
What is the problem?

thanks,
alex

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

public class LPTry {

public static void main(String[] args) {
JFrame jf = new JFrame();
jf.getContentPane().setLayout(new BorderLayout());

JLabel tlabel = new JLabel("east");

jf.getContentPane().add(tlabel, BorderLayout.EAST);

JLayeredPane lpane = new JLayeredPane();
tlabel = new JLabel("center bottom");
lpane.add(tlabel, JLayeredPane.DEFAULT_LAYER);

jf.getContentPane().add(lpane, BorderLayout.CENTER);

jf.pack();
jf.setVisible(true);

}
}

.