This script contains the same PHP code as Section PHP Sessions: Using PHP's isset Function of tizag.com's tutorial PHP Sessions - Why Use Them? Namely:
<?php
session_start();
if(isset($_SESSION['views']))
$_SESSION['views'] = $_SESSION['views']+ 1;
else
$_SESSION['views'] = 1;
echo "views = ". $_SESSION['views'];
?>
views = 1