Using global data in actionPerformed function

Question

i am giving the code snipet and want to know how is it possible to use an integer array in the actionPerformed function. If i use in the it as in the code following error is generated.
Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
The code is:
package ntictactoe;
import java.awt.Font;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
* @author root
public class TBoard extends javax.swing.JFrame{
/** Creates new form TBoard */
JButton buttons[];
int pos;
int board[];
public TBoard(int gridSize) {
// initComponents();
if(gridSize<3 || gridSize>6) {
JPanel Mp = new JPanel();
JOptionPane.showMessageDialog(Mp,"Invalid Grid Size, \n Please Enter size between 3 and 6");
System.exit(0);
} else{
int k=gridSize*gridSize;
jPanel1 = new javax.swing.JPanel();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
jPanel1.setLayout(new java.awt.GridLayout(gridSize, gridSize, 1, 1));
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addContainerGap()
.addComponent(jPanel1, javax.swing.GroupLayout.DEFAULT_SIZE, 412, Short.MAX_VALUE)
.addContainerGap())
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addContainerGap()
.addComponent(jPanel1, javax.swing.GroupLayout.DEFAULT_SIZE, 350, Short.MAX_VALUE)
.addContainerGap())
ActionListener l = new ActionListener() {
public void actionPerformed(ActionEvent e) {
JButton button = (JButton)e.getSource();
String ac = button.getActionCommand();
System.out.println("ac = " + ac);
button.setEnabled(false);
button.setText("X");
pos=Integer.parseInt(ac);
board[pos]=1;
//System.out.println(""+pos);
// computerResponse(board[pos]);
int i;
JButton buttons[]= new JButton[k];
int board[]=new int[k];
for(i=0;i<k;i++){
buttons=new JButton("");
jPanel1.add(buttons[i]);
buttons[i].addActionListener(l);
buttons[i].setText(""+i);
board[i]=0;
System.out.println(board[0]);
pack();
void computerResponse(int pos){
// board[pos]=1;
System.out.println(""+pos);
/** This method is called from within the constructor to
* initialize the form.
* WARNING: Do NOT modify this code. The content of this method is
* always regenerated by the Form Editor.
// <editor-fold defaultstate="collapsed" desc=" Generated Code ">
private void initComponents() {
jPanel1 = new javax.swing.JPanel();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
setResizable(false);
jPanel1.setLayout(new java.awt.GridLayout(4, 4, 1, 1));
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addContainerGap()
.addComponent(jPanel1, javax.swing.GroupLayout.DEFAULT_SIZE, 344, Short.MAX_VALUE)
.addContainerGap())
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addContainerGap()
.addComponent(jPanel1, javax.swing.GroupLayout.DEFAULT_SIZE, 269, Short.MAX_VALUE)
.addContainerGap())
pack();
}// </editor-fold>
* @param args the command line arguments
public static void main(String args[]) {
/*int gridSize = Integer.parseInt(JOptionPane.showInputDialog(null,
"Enter the Grid size",
"Tic Tac Toe",
JOptionPane.QUESTION_MESSAGE));*/
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
new TBoard(Integer.parseInt(JOptionPane.showInputDialog(null,
"Enter the Grid size",
"Tic Tac Toe",
JOptionPane.QUESTION_MESSAGE))).setVisible(true);
/* public void actionPerformed(ActionEvent e) {
int i;
JButton bt = (JButton)(e.getSource());
for(i=0;i<16;i++){
if(bt==buttons[i]){
System.out.println(buttons[i]);
break;
// Variables declaration - do not modify
private javax.swing.JPanel jPanel1;
// End of variables declaration

Answer 1

First, read this: http://forum.java.sun.com/help.jspa?sec=formatting
Then: try posting again.
Then: tell us where the exception happens.
better yet: look at it, read the exception's API docs for its causes and fix it yourself.