mssql connect problem from php4 on linux

Hi everyone I am trying to set up php4, apache on linux redhat 7 to connect to Microsoft SQL server version 7 or 2000. I have downloaded the sybase open client libraries and installed the common rpm and the openclient rpm. When i try a mssql_connect("...","user","pass"); I get: Warning: Sybase: Unable to connect in ...[the file name] If I then do a mssql_get_last_message(); I receive: ct_connect(): network packet layer: internal net library error: Net-Library operation terminated due to disconnect Does anyone know what is going on and what I should do next to get this to work? Any help would be greatly appreciated. Thanks in advance, Pete