// instance static field for singleton object

private static $instance;

// static session id

private static $id;

// private constructor according to singleton pattern

private function __construct() {

session_start();

self::$id = session_id();

}

// private clone according to singleton pattern

private function __clone() {}

// get session instance avoiding creation if already exists

public static function getInstance() {

if(!isset(self::$instance)) {

self::$instance = new KidSession();

}

return self::$instance;

}

// destroy session instance

public function destroy() {

foreach ($_SESSION as $var => $val) {

$_SESSION[$var] = null;

}

session_destroy();

}

// get requested variable

public function __get($var) {

return $_SESSION[$var];

}

// set variable into session instance

public function __set($var, $val) {

$_SESSION[$var] = $val;

}