if (isset($_SESSION['page_stack'])) {
    	// remove any redundant entries in $_SESSION['page_stack']
        $_SESSION['page_stack'] = comparePageStacks($_SESSION['page_stack'], $page_stack);
    } // if

    if (isset($_SESSION['page_stack'])) {
        if (basename($PHP_SELF) == 'help.php') {
            // continue
        } else {
            // remove any redundant entries in $_SESSION['page_stack']
            $_SESSION['page_stack'] = comparePageStacks($_SESSION['page_stack'], $page_stack);
        } // if
    } // if