// Addition program
import java.applet.Applet;
import java.awt.*;    		// import the java.awt package
import java.awt.event.*;  	// import the java.awt.event package

public class Addition2 extends Applet implements ActionListener {
   	Label prompt;      		// message that prompts user to input
   	TextField input;   		// input values are entered here
   	int number;        		// variable that stores input value
   	int sum;           		// variable that stores sum of integers

   	// setup the graphical user interface components and 
   	// initialize variables
   	public void init() {
		setBackground( Color.yellow ); // set the background to yellow
		
      	prompt = new Label( "Enter integer and press Enter:" );
      	add( prompt );  	// put prompt on applet 

  		input = new TextField( 10 );
      	add( input );   	// put input TextField on applet

      	sum = 0;        	// set sum to 0

      	// "this" applet handles action events for TextField input
      	input.addActionListener( this );
   	}

   	public void paint( Graphics g ) {
   		g.drawString( "The current sum is  " + sum, 40, 60 );
   	}	

   	// process user's action in TextField input 
 	public void actionPerformed( ActionEvent e ) {
     	// get the number and convert it to an integer
      	number = Integer.parseInt( e.getActionCommand() );

      	sum = sum + number;   // add number to sum
      	input.setText( "" );  // clear data entry field
      	showStatus( Integer.toString( sum ) );  // display sum
      	repaint();
   	}
}