@AdamGundryJun 19.2004 — #First you should read [url=http://uk.php.net/manual/en/security.globals.php]this[/url] and decide whether you really need register_globals on - there are security issues with it.
If so, you will need to edit your php.ini file (which will be stored somewhere on your server's path, depending on operating system and system configuration). It contains the line "register_globals = off" which you need to change to "register_globals = on".
@shimonJun 21.2004 — #You shouldn't even be thinking about trying to enable it - have you ever tried debuggering someone else's 4,000 line-long script which gives you no idea where $id comes from?