From Documentation
Whether an event is supported or not depends upon the component. Additionally an event is sent after the component’s content is updated.
if (!empty($_SERVER['HTTP_CLIENT_IP'])) $ip=$_SERVER['HTTP_CLIENT_IP']; else if (!empty($_SERVER['HTTP_X_FORWARDED_FOR'])) $ip=$_SERVER['HTTP_X_FORWARDED_FOR']; else $ip=$_SERVER['REMOTE_ADDR']; ?>