Look at the following GUI application class and indicate by line number the changes that should be made to convert this to an applet using Swing: 

1 public class SimpleWindow extends JFrame 2 { 3 public SimpleWindow() 4 { 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 } } // Set the title. setTitle("A Simple Window"); // Specify what happens when the close button is clicked. setDefaultCloseOperation (JFrame.EXIT_ON_CLOSE) ; // Add a label. JLabel label = new JLabel("This is a simple window."); add (label); // Pack and display the window. pack(); setVisible(true);