Java Program to Display Sum of Two Numbers using Swings

import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
class Addition extends JFrame implements ActionListener 	  
{

 JLabel l1, l2;
 JTextField t1, t2, t3;
 JButton b1; 
 public Addition() 
{

  l1 = new JLabel("Enter the First Number:");
  l1.setBounds(20, 10, 100, 20);    	
  t1 = new JTextField(10);
  t1.setBounds(120, 10, 100, 20);
  l2 = new JLabel("Enter the Second Number:");
  l2.setBounds(20, 40, 100, 20);    
  t2 = new JTextField(10);
  t2.setBounds(120, 40, 100, 20);
  b1 = new JButton("Sum of Two Numbers:");
  b1.setBounds(20, 70, 80, 20);
  t3 = new JTextField(10);
  t3.setBounds(120, 70, 100, 120);
  add(l1);
  add(t1);
  add(l2);
  add(t2);
  add(b1);
  add(t3);
  b1.addActionListener(this);   	
  setSize(400,300);
  setLayout(null);
  setVisible(true);
  setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);  
}
@Override
public void actionPerformed(ActionEvent e)    	
{
  if(e.getSource()==b1){

        int n1 = Integer.parseInt(t1.getText()); 
        int n2 = Integer.parseInt(t2.getText()); 
        int sum = n1 + n2;
        t3.setText(String.valueOf(sum));
}
public static void main(String args[])
{
   new Addition();
}
}