Quick question about my alignment ...

Why is my JMenuBar aligned in the centre?

As well as my buttons in the buttom panel ...

I would like to have the top menubar aligned to the left of the panel!

Any ideeas?

/*
* Invaders.java
*
* Created on 27 May 2005, 15:06
*/

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

/**
* This class creates the JFrame, adds a quit button
* to it and contains the <b>main</b> method to start the
* program
*
*/
public class Invaders
implements ActionListener
{
//The game window
private JFrame frame = null;

//The buttons
private JButton quit = null;
private JButton restart = null;
private JLabel name = null;
private JLabel score = null;

private JMenuBar menubar;
private JMenu file, options;
private JMenuItem restart_game, quit_game, change_speed, change_rows, change_name;

//The JPanel which runs and draws the game
private Game game = null;

/** Creates a new instance of Invaders */
public Invaders()
{
//Create the window and buttons
createGUI();

//Make our window get the focus
frame.getContentPane().requestFocusInWindow();

//Don't allow the focus to move around in our window
frame.getContentPane().setFocusTraversalKeysEnabled(false);

//Show the frame to the player
frame.setVisible( true );
}

/**
* Create the JFrame and all user interface components
*/
private void createGUI()
{
//Setup the frame with an appropriate title
frame = new JFrame( "Invaders From Space!" );

//Make the window a decent size and position it's top
//left corner at 0,0
frame.setBounds( 0, 0, Game.GAME_WIDTH, Game.GAME_HEIGHT );

//Set the layout of the window
frame.getContentPane().setLayout( new BorderLayout() );

//Add the button to the window
createButtons();

//Creates a dialog box with a dropdown menu asking the player to make a selection
Object[] possibleValues = { "1", "2", "3", "4" };
Object selectedValue = JOptionPane.showInputDialog(null,
"Select number of rows of Aliens", "",
JOptionPane.INFORMATION_MESSAGE, null,
possibleValues, possibleValues[0]);

if (selectedValue == null)
{
selectedValue = "1";
}

int numRows = Integer.parseInt((String)selectedValue);

selectedValue = null;

//Displays a drop-down dialogue box asking the player to select the speed.
Object[] possibleSpeedValues = { "Slow", "Medium", "Fast" };
selectedValue = JOptionPane.showInputDialog(null,
"Select speed", "",
JOptionPane.INFORMATION_MESSAGE, null,
possibleSpeedValues, possibleSpeedValues[0]);

if (selectedValue == null)
{
selectedValue = "Slow";
}
String speedString = (String)selectedValue;

//Whenever a value is chosen from the dropdown box,
//the speed is incremented by one
int speed = 0;
if (speedString.equals("Slow"))
{
speed = 1;
}
else if (speedString.equals("Medium"))
{
speed = 2;
}
else if (speedString.equals("Fast"))
{
speed = 3;
}

//Instatiate the class the runs the game
game = new Game(score, numRows, speed);

//Add the game to the middle of the JFrame
frame.getContentPane().add(game, BorderLayout.CENTER );

//Add a listener to the window so it closes
//properly
frame.addWindowListener(
new WindowAdapter()
{
public void windowClosing( WindowEvent e )
{
//Call the exit method
doExit();
}
}
);

}

/**
* Create buttons needed by the game
*/
private void createButtons()
{
//Create a JPanel to put the buttons in
JPanel p = new JPanel( );

//Create a JPanel to put the menu bar in
JPanel t = new JPanel( );

//Initialise the buttons
quit = new JButton( "Quit" );
restart = new JButton( "Restart" );
name = new JLabel (JOptionPane.showInputDialog("Please type your name"));
name.setForeground(Color.BLACK);
name.setFont(new Font("Arial", Font.BOLD, 18));

score = new JLabel ("0");
score.setForeground(Color.RED);
score.setFont(new Font("Arial", Font.BOLD, 18));

//Add an action listener to the buttons
//so we know when they are pressed
quit.addActionListener( this );
restart.addActionListener( this );

//Add the buttons to the button panel
p.add( quit );
p.add( restart );
p.add( name );
p.add( score );

//Add the button panel to the bottom of the
//window
frame.getContentPane().add( p, BorderLayout.SOUTH );

//Initialise the menubar
menubar = new JMenuBar();

restart_game = new JMenuItem("Restart Game");
quit_game = new JMenuItem("Quit Game");
change_speed = new JMenuItem("Change Speed");
change_rows = new JMenuItem("Change Rows");
change_name = new JMenuItem("Change Name");

//Add the panel to the top of the
//window
frame.getContentPane().add( t, BorderLayout.NORTH);

//Add the menubar to the panel
t.add( menubar );

file = new JMenu("File");
menubar.add(file, BorderLayout.WEST);

menubar.add( new JSeparator());

options = new JMenu("Options");
menubar.add(options, BorderLayout.WEST);

restart_game.addActionListener(this);
quit_game.addActionListener(this);

file.add(restart_game);
file.add(quit_game);
options.add(change_speed);
options.add(change_rows);
options.add(change_name);

}

/**
* Make sure the application exits properly
*/
private void doExit()
{
System.exit( 0 );
}

/**
* Listen for button presses, etc.
*/
public void actionPerformed( ActionEvent e )
{
//If the quit button is pressed
if( e.getSource() == quit )
{
//Exit the program
doExit();
}

//If the restart button is pressed
if( e.getSource() == restart )
{
game.restart();
//Screen focus changes to the game window
game.grabFocus();
}

//If the restart button is pressed
if( e.getSource() == restart_game )
{
game.restart();
//Screen focus changes to the game window
game.grabFocus();
}

//If the restart button is pressed

if( e.getSource() == quit_game )
{
doExit();
}

}

/**
* @param args the command line arguments
*/
public static void main(String[] args)
{
new Invaders();
}

}