Exception in thread "main" java.lang.NullPointerException

Hi this is the exception i am getting when i am trying to run this application:
Exception in thread "main" java.lang.NullPointerException

thanks in advance..

package com.inventive.StockMarketTrading;

import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.event.ActionEvent;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;

import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTable;

/**
* @author inv
*
*/
public class TransactionsView extends JFrame{
private boolean DEBUG = true;

// Constructor Which takes care of the Components layout
public TransactionsView()
{
//super("JTableDemo");
TransactionsModel model = new TransactionsModel();
TransactionsTableSorter sorter = new TransactionsTableSorter(model);
JTable table = new JTable(model);
sorter.addMouseListenerToTable(table);
table.setPreferredScrollableViewportSize(new Dimension(500, 70));
JScrollPane scrollPane = new JScrollPane(table);
getContentPane().add(scrollPane, BorderLayout.CENTER);

addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent e) {
System.exit(0);
}
});
}

public static void main(String[] args)
{
System.out.println("inside main method");
TransactionsView view = new TransactionsView();
System.out.println("after constructor call");
view.pack();
view.setVisible(true);
}

}