php - Facebook app not running? -

i bought script facebook app, , seems not loading page @ if part of code added. if remove it, app won't request user send invites. essential me.

if ($user) { $fbid = $user; $log -> log_install($fbid); }  

log_install function:

function log_install($facebookid) {        $country = $this->getcountry();     $ip = $this->ipaddress();     $datestamp = date("y-m-d");     $date = date_create();     $timestamp = date_timestamp_get($date);     // first check , abort logging if facebookid exists;     if($this->check_id($facebookid) != 1)     {         mysql_query("insert installs (facebookid, country, ip, datestamp, timestamp) values ('$facebookid', '$country', '$ip', '$datestamp', '$timestamp')");     }  } 

how approach this? can provide further info if not enough. have basic php knowledge it's not enough troubleshoot this