<?php
session_start();
?>
<!DOCTYPE html>
<html lang="en-US">
<head>
<meta charset="UTF-8">
<title>Session Counter</title>
</head>
<body>
<?php
$counter = 0;
if (isset($_SESSION['counter'])) {
$counter = $_SESSION['counter'] + 1;
}
$_SESSION['counter'] = $counter;
echo "<h1>Session Counter: $counter</h1>";
?>
</body>
</html>