private function _userids($users)
	{
		$db = \App::get('db');

		if (empty($db))
		{
			return false;
		}

		$usernames = array();
		$userids = array();

		if (!is_array($users))
		{
			$users = array($users);
		}

		foreach ($users as $u)
		{
			if (is_numeric($u))
			{
				$userids[] = $u;
			}
			else
			{
				$usernames[] = $db->quote($u);
			}
		}

		if (empty($usernames))
		{
			return $userids;
		}

		$set = implode($usernames, ",");

		$sql = "SELECT id FROM `#__users` WHERE username IN ($set);";

		$db->setQuery($sql);

		$result = $db->loadColumn();

		if (empty($result))
		{
			$result = array();
		}

		$result = array_merge($result, $userids);

		return $result;
	}