php 5 and register_globals=off gives lotsa errors

Hi to all. I am having huge problems running my script, which worked fine on a server with php 4 and register_globals turned on, on a server with php 5 and register_globals turned off. I get errors around the area in my script where I use $_GET (not the only error). For example the following code on my index.php file which like many other sites I know, handles quite a large amount if(action=="main"); etc etc. : <? $action = $_GET["action"]; //line 55

$sid = $_GET["sid"];       //line 56
$page = $_GET["page"];     //line 57
$who = $_GET["who"];       //line 58

?> When I go to http://chillinglounge.net (where the error is located) I get the following error message(s): Notice: Undefined index: action in C:\websites\chillinglounge.net\public_html\index.php on line 55 Notice: Undefined index: sid in C:\websites\chillinglounge.net\public_html\index.php on line 56 Notice: Undefined index: page in C:\websites\chillinglounge.net\public_html\index.php on line 57 Notice: Undefined index: who in C:\websites\chillinglounge.net\public_html\index.php on line 58 Now if you would look at exactly the same script at http://ranterswap.net you'd see absolutely no errors. That's where I need your help. I know what is causing this error. I believe it's the fact that register_globals is turned off. But what I really want to know is: How do I fix it without trying to turn register_globals on via .htaccess (because it doesn't work)? Is there a function or some magic script that would to the trick? Or do I have to recode my entire script and how?