Java programming query

import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
import java.io.*;
//<applet code=Login height=300 width=400></applet>
public class Login extends JApplet implements ActionListener
{
 JTextField textCustName;
 JPasswordField textPassword;
 JLabel labelCustName, labelPassword;
 JButton loginButton;
 
 public void init()
 {
  createApplet();  
 }
 
 public void createApplet()
 {
  JPanel panel;
  panel = new JPanel();
  getContentPane().add(panel);
  panel.setLayout(new FlowLayout());
  labelCustName = new JLabel("Customer login Name:");
  textCustName = new JTextField(10);
  labelPassword = new JLabel("Password:");
  textPassword = new JPasswordField(10);
  loginButton = new JButton("Login");
  panel.add(labelCustName);
  panel.add(textCustName);
  panel.add(labelPassword);
  panel.add(textPassword);
  panel.add(loginButton);
  loginButton.addActionListener(this);     
 }
 public void actionPerformed(ActionEvent evt)
 {
  Object obj = evt.getSource();
  if (obj == loginButton)
  {
   String entry = textCustName.getText() + ":" + new String(textPassword.getPassword());
   try
   {
    RandomAccessFile logfile = new RandomAccessFile("Customer.txt","rw");
    logfile.seek(logfile.length());
    logfile.writeBytes(entry);    
   }
   catch(IOException e)
   {
    showStatus("Cannot write on to the logfile"+e);
   }
  }
 }
}