Frame refresh problem

Hi Friend,

Try the following code:

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

class FrameLocation {

public static void main(String[] args){
JFrame frame=new JFrame();
JButton b=new JButton("Submit");
frame.add(b);
frame.setVisible(true);
frame.pack();
b.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent ae){
JFrame f=new JFrame();
Dimension d = Toolkit.getDefaultToolkit().getScreenSize();
f.setLocation((int)d.getWidth()/2 - (int)f.getPreferredSize().getWidth()/2,
(int)d.getHeight()/2 - (int)f.getPreferredSize().getHeight()/2);
f.setVisible(true);
f.setSize(300,100);
}
});
}
}

Thanks