Question : Understanding why there are no $_POST["myvar"] and how this works on linux but not on windows?

I've been given some PHP which works fine on a none windows web server and when i try to run the php on windows, theres some $_POST["myvarl"] obviously missing.

Do none windows systems no need $_POST["myvar"] ?

TIA

Answer : Understanding why there are no $_POST["myvar"] and how this works on linux but not on windows?

You should NEVER set register_globals!
http://php.net/manual/en/security.globals.php