if (!is_object($USER)) $USER = new CUser;
$arAuthResult = $USER->Login("логин", "пароль", "N", "Y");
$APPLICATION->arAuthResult = $arAuthResult;
в конце скрипта: $USER->Logout();
$arAuthResult = $USER->Login("логин", "пароль", "N", "Y");
$APPLICATION->arAuthResult = $arAuthResult;
в конце скрипта: $USER->Logout();
, ($order="desc"