Basic Addition Program in Java AWT

import java.awt.*;
import java.awt.event.*;
 
//Basic Addition Program in Java AWT
class MyApp extends Frame implements ActionListener {
 
	Label l1, l2, l3;
	TextField txt1;
	TextField txt2;
	Button b;
 
	public MyApp() {
		super("Tutor Joes");
		setSize(1000, 600);// w,h
		setLayout(null);
		setVisible(true);
 
		l1 = new Label("Enter The Value 1 : ");
		l1.setBounds(10, 50, 100, 30);
 
		txt1 = new TextField();
		txt1.setBounds(150, 50, 250, 30);
 
		l2 = new Label("Enter The Value 2 : ");
		l2.setBounds(10, 100, 100, 30);
 
		txt2 = new TextField();
		txt2.setBounds(150, 100, 250, 30);
 
		b = new Button("Click Me");
		b.setBounds(150, 150, 100, 30);
		b.addActionListener(this);
 
		l3 = new Label("--");
		l3.setBounds(10, 200, 300, 30);
 
		add(l1);
		add(txt1);
		add(l2);
		add(txt2);
		add(b);
		add(l3);
 
		// Close Button Code
		this.addWindowListener(new WindowAdapter() {
			public void windowClosing(WindowEvent we) {
				System.exit(0);
			}
		});
	}
 
	@Override
	public void actionPerformed(ActionEvent e) {
		String s1 = txt1.getText();
		String s2 = txt2.getText();
		if(s1.isEmpty() || s2.isEmpty()) {
       	 l3.setText("Please Enter The data");    
       }else {
	        int a = Integer.parseInt(s1);    
	        int b = Integer.parseInt(s2);    
	        int c = a+b;
	        String result = String.valueOf(c);    
	        l3.setText("Total :"+result);    
	        }
 
	}
 
}
 
public class app {
	public static void main(String[] args) {
		MyApp frm = new MyApp();
	}
 
}