<script language="JavaScript">
//program one

document.writeln ("2 + 2 = 4");
alert (2 + 2);
</script>

<script language="JavaScript">
//program two

var number1 = 2;
var number2 = 2;
document.writeln(number1 + " + " + number2 + " = " + number1 + number2);
alert(number1 + number2);
</script>

<script language="JavaScript">
//program three

var number1 = 2;
var number2 = 2;
var answer = number1 + number2;
document.writeln(number1 + " + " + number2 + " = " + answer);
alert(answer);
</script>