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

public class Examp extends Frame implements ActionListener
{
  private int numClicks;
  private Button b;
  private Button exit;
  public Examp()
  {
    this.numClicks = 0;
    this.setLayout(null);
    this.b =  new Button("Push me");
    this.add(this.b);
    this.b.addActionListener(this);
    this.b.setBounds(30, 30, 100, 40);
    this.exit = new Button("Exit");
    this.exit.addActionListener(this);
    this.exit.setBounds(150, 30, 100, 40);
    this.add(this.exit);
    this.setSize(360, 360);
    this.setTitle("First example");
    //this.setBackground(Color.gray);
    this.setVisible(true);
  }
  
  public void actionPerformed(ActionEvent e)
  {
    Button which = (Button)e.getSource();
    if(which == this.b)
    {
      if(this.numClicks % 2 == 0)
      {
        this.setBackground(Color.red);
      }
      else
      {
        this.setBackground(Color.yellow);
      }
      this.numClicks++;
    }
    else
    {
      System.exit(0);
    }
  }

  public static void main(String args[])
  {
    Examp e = new Examp();
  }
}