Java "Addition"

nah kalo program ini tentang tambah2an gitu pake dialog box.

import javax.swing.JOptionPane;

public class Addition
{
public static void main ( String args [] )
{
String firstNumber,
secondNumber;
int number1,
number2,
sum;

firstNumber =
JOptionPane.showInputDialog( “Enter first integer” );

secondNumber =
JOptionPane.showInputDialog( “Enter second integer” );

number1 = Integer.parseInt( firstNumber );
number2 = Integer.parseInt( secondNumber );

sum = number1 + number2;

JOptionPane.showMessageDialog(
null, “The sum is ” + sum, “Results”,
JOptionPane.PLAIN_MESSAGE );

System.exit( 0 );
}
}