Help me pls. i so new in this

Question

Pls tell me why this doesn't close the window.
import java.awt.*;
import java.awt.event.*;
class TicTacGui extends Frame {
          Button button[];
     TicTacGui(){
          Frame mainframe = new Frame();
          MenuBar mainmenu = new MenuBar();
          Menu m1 = new Menu("File");
          Panel forButtons= new Panel();
          Panel forText= new Panel();
          m1.add(new MenuItem("Exit"));
          mainmenu.add(m1);
          mainframe.add(forButtons, BorderLayout.CENTER);
          mainframe.add(forText, BorderLayout.SOUTH);
          mainframe.setMenuBar(mainmenu);
          forButtons.setLayout(new GridLayout(3,3,1,1));
          //adding buttons               
     button=new Button[9];
     for(int i=0;i<9;i++)
     button[i] = new Button("Button");
     forButtons.add(button);
          mainframe.setSize(300,300);
          mainframe.setVisible(true);
          //Listener for exiting the window
          addWindowListener( new WindowAdapter() {
               public void windowClosing( WindowEvent event ) {
          System.exit( 0 );
public static void main(String args[]) {
          TicTacGui tic = new TicTacGui();

Answer 1

mainframe is not the same thing as your instance of TicTacGui... there is no need for mainframe. What you are doing is adding everything to mainframe, then showing mainframe, and adding the WindowListener to your instance of TicTacGui... instead, get rid of mainframe and use the instance of TicTacGui that you are creating for everything. since TicTacGui extends frame it gets all of the methods in frame. hope that made sense