// W3app.java  demonstrate a label and a button

import java.awt.*;
import java.awt.event.*;
import java.applet.*;

public class W3app extends Applet implements ActionListener {
    Button helloButton;
    boolean original=true;
    
  public void init()
  {
    // The init is responsible for setting
    // up the initial buttons and color background.
    setBackground(Color.cyan);
    setForeground(Color.black);
    setLayout(new FlowLayout(FlowLayout.CENTER, 15, 10));
    
    add(new Label("a label")); // a label

    helloButton = new Button("Hello World");  // a button
      helloButton.addActionListener(this);
      add(helloButton);
      
    setSize(200,200);
    setBackground(Color.green);
    setForeground(Color.black);
    setVisible(true);
  }

  public void actionPerformed(ActionEvent e) {
    if (e.getSource() == helloButton)
    {
      if(original)
      {
        setForeground(Color.white);
        setBackground(Color.red);
        // change text to Good by World
        original = !original;
      }
      else
      {
        setBackground(Color.green);
        setForeground(Color.black);
        original = !original;
      }
    }
  }
}