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

public class HelloApplet extends Applet implements ActionListener{

Button bt1 = new Button("red");
Button bt2 = new Button("blue");
Button convert = new Button("convert dollar to pound");
TextField txt1= new TextField(20);
Label lb1= new Label("Pound");
Label lb2= new Label("Dollar");
TextField txt2= new TextField(20);
public void init()
{
System.out.println("I am called once when applet is initialized");
add(bt1);
add(bt2);

add(txt1);
add(lb2);
add(txt2);
add(lb1);

txt1.addActionListener(this);
bt1.addActionListener(this);
convert.addActionListener(this);
}
/*
Note that init() start() stop() and destroy() methods are in the Applet 
superclass and you are overriding them
*/
public void start()
{
//this will add button to the applet
setBackground(Color.yellow);
add(convert);
//this will add the listener to the button bt2 object
bt2.addActionListener(this);
System.out.println("I am called whenever you activate my applet browser");

}
public void stop()
{
System.out.println("I am called whenever you minimize the browser");
}
public void destroy()
{
System.out.println("I am called whenever you exit the applet");
}
public void paint(Graphics g)
{
 g.drawString("Java in Unix.....", 50, 150);

}

public void actionPerformed(ActionEvent e)
{
  if(e.getSource()==bt1)
  {
    setBackground(Color.red);
 //   add(bt3);
  }
 else if (e.getSource()==convert)
 {
   double d;
   d= Double.parseDouble(txt1.getText());
  txt2.setText(Double.toString(d*.4839));

  }
 else if(e.getSource()==txt1)
 {
   txt2.setText(txt1.getText());
  }
  else 
  {
   setBackground(Color.blue);
  }
}


}//end applet