connect to MSsql server db, freeTDS install

hi. I have some php pages that connects to db server ms sql. In these pages there is a call to function "mssql_connect()2 and not only this. but when I try to run these page on mac os x server I see the common error because php was not configured for mssql.

what can I do?
I have read to solve the problem, install freeTDS, is it ok?
what ca I do to install freeTDS? is there an alternative to work with mssql in php?
thank's a lot
fil