That require() line is pretty messed up. The argument to require() needs to be a file pathname. I'm not sure what the $_SERVER = portion is doing in there, plus the or die(mysql_error()) doesn't make much sense there, either, as require() has nothing to do with MySQL (although the file it calls might).
Normally it would be something like:
require '/home/bob/htdocs/Config/config.php';
Or perhaps you wanted to use the $SERVER['DOCUMENT_ROOT'] super-global to do:
require $_SERVER['DOCUMENT_ROOT'] . '/Config/config.php';