$test=$_GET['test'];
$postvar=$_POST['postvar'];
If the page works, then you have register_globals turn off.
If that is the case you have a few options, reinstall php with register_globals on. Or, at the begining of your scripts set every variable from where it should be coming from. That can be very time consuming, however if you are used to coding with Java,C,C++,ASP or any of a number of other languages it isn't that big of a deal. It is a nice feature of PHP but it can also be a security risk.
I am sure there are other things you could do, I just don't know what
HTH