User::isActive

static function isActive($userId)
{
	$userId = intval($userId);
	if(!$userId)
	{
		return false;
	}

	$user = UserTable::getList(array('filter' => array(
		'=ID' => $userId
	), 'select' => array(
		'ID', 'ACTIVE'
	)))->fetch();

	return $user['ACTIVE'] == 'Y';
}