protected function getLoginCredential($credentials = array())
	{
		$loginField = $this->app['config']['auth.credentials.login'];

		if (isset($credentials[$loginField]))
		{
			return $credentials[$loginField];
		}
		else if (Input::has($loginField))
		{
			return Input::get($loginField);
		}
		else if (isset($credentials['user_login']))
		{
			return $credentials['user_login'];
		}
		else if (isset($credentials['log']))
		{
			return $credentials['log'];
		}

		throw new InvalidArgumentException("Login field not found");

	}