import javax.swing.*;
public class LookAndFeel{
public static void main(String[] args){
JFrame F = new MainFrame();
F.setVisible(true);
} // end of main
}//end of class LookA
import javax.swing.*;
import java.awt.event.*;
public class MainFrame extends JFrame{
JDesktopPane desktop;
public MainFrame(){
super("MainFrame-Look And Feel");
setBounds(1
import javax.swing.*;
import java.awt.*;
import java.util.*;
import javax.swing.tree.*;
public class DemoTree extends JInternalFrame{
public DemoTree(){
super("Demo Tree Structure", tr