How to beat a proxy server

[Areku]

Hi!

I'm on Spain and main ISP put a proxy for the whole country so now people coming from any region can enter multiple times even if I ban them, since I'd be banning proxy IP.

Someone pointed out this function to retrieve the REAL IP:

PHP Code:

function ipReal(){

if ($tmp=getenv("HTTP_X_FORWARDED_FOR")) {
    $tmpip=explode(",",$tmp);
    return trim($tmpip[0]); }
else return getenv("REMOTE_ADDR");
} 


And claimed I have to paste it everywhere an IP is traced.

Can anyone in here be more specific OR point me to a hack that would allow me to ban people behind a proxy?

Thanks!