JavaScript Calculate numbers

Calculate numbers

<html>
<head>

<script language="JavaScript">
<!-- hide

function calculation() {
  var x= 12;
  var y= 5;

  var result= x + y;

  alert(result);
}

// -->
</script>

</head>
<form>
<input type="button" value="Calculate" onClick="calculation()">
</form>

</body>
</html>