dbx complains that mssql is not loaded

Im running Apache 1.3.7 under RedHat 7.2 I've recompiled apache to load PHP as a module I've installed Freedts PHP has been recompiled to include mssql support (--with-mssql=/usr/local where Freedts puts its files) and with dbx support The following call in a php script: $link = dbx_connect (DBX_MYSQL, "my.db.sever", "db", "username", "password"); results in this error message: Warning: dbx: module 'dbx_mssql' not loaded. in /var/www/html/test.php exactly what is it that should have been loaded? And where? Should i load mssql.so in php.ini? If yes, wher do i find it (its nowhere in my system)