session_unregister
session_write_close
Session Функции
PHP Manual

# session_unset

(PHP 4, PHP 5)

session_unset — Free all session variables

### Описание

void session_unset ( void )

The session_unset() function frees all session variables currently registered.

### Возвращаемые значения

Эта функция не возвращает значения после выполнения.

### Примечания

> Замечание: If $_SESSION (or $HTTP_SESSION_VARS for PHP 4.0.6 or less) is used, use unset() to unregister a session variable, i.e. unset ($_SESSION['varname']);.

Предостережение

Do NOT unset the whole $_SESSION with unset($_SESSION) as this will disable the registering of session variables through the $_SESSION superglobal.

session_unregister
session_write_close
Session Функции
PHP Manual