I work in a large educational institution, using PHP and MS SQL Server, and I can't convince the sysadmins to install PDO because the SQL Server PDO bindings have a big red EXPERIMENTAL sign on the page (http://php.net/manual/en/ref.pdo-dblib.php). So I'm stuck using 'mssql_' functions, I'm afraid.

You can try the driver released from Microsoft http://sqlsrvphp.codeplex.com/. Haven't tried it myself though.

I'd suggest that a bigger problem with your situation is that you're trying to use MSSQL with PHP...