Connecting to MSSQL DB from LAMP server (connection string)

Hi,
I installed a LAMP server, got the sybase and freetds installed, connecting to mssql through isql and tsql work flawlessly. When checking PHP it actually says the mssql is installed.
However, I do get the following error when using a PHPRunner created site:
Warning: mssql_connect(): Unable to connect to server: www.myserver.com in /usr/share/nginx/html/include/dbconnection.mssql.unix.php on line 8
Fatal error: in /usr/share/nginx/html/include/dbconnection.mssql.unix.php on line 10
Now I think this has to do with the line in /include/dbcommon.php: $ODBCString = "Provider=SQLOLEDB;Server=
What should I put in for Provider? SQLOLEDB doesn't work and FreeTDS doesn't work either.
Any suggestions?