[Phpwebsite-developers] Error installing whoisonline pluging

[<al...@yu...>]

I'm tring to install whoisonline as the setup readme said
http://www.myserver.com/mod/phpwhoisonline/phpwhoisonline_setup.php

and return this

Warning: Failed opening '../../open_session.php' for inclusion
(include_path='.:/usr/share/pear') in
/var/www/html/arcoiris/mod/phpwhosonline/phpwhosonline_setup.php on line 17

Warning: Failed opening '../../config.php' for inclusion
(include_path='.:/usr/share/pear') in
/var/www/html/arcoiris/mod/phpwhosonline/phpwhosonline_setup.php on line 21
Unable to select database

what's going wrong?????