Custom name check in register.php / log IP of each visit?

[Wastl]

Hello,

I have two questions about custom functions in vBulletin.

1. I have a custom check function in register.php that checks if the name with which the user registers already exists in a database table. Currently I added code to the "start add member" section of register.php:
   
   PHP Code:

   $exist    = MYSQL_QUERY(some SQL query);
if(!MYSQL_NUM_ROWS($exist)){
    eval(standard_error(fetch_error('namenotexistant')));
    exit;
} 

   Each time I update the forum, I have to add this code again. Is this something I could do with some kind of plugin that stays unaffected by updates? At least the phrase "namenotexistant" stays active for minor upgrages.
2. Can I activate somehow logging the IP address each time a user enters the forum with user name and password and not only on registration and for each post? I am having problems with hacked forum accounts and people do only read but not post and looking up IPs in the apache log files is very time consuming and I always need time and URL of the activity.

Thanks a lot for any hint