How to start PgSQL on FreeBSd to the port 5432

Hello,
       We are using a FreeBSD 4.6.2 and on that have installed PostGreSQL
7.2 and PHP. We are able to start the PGSQL server but when we try to open
a database  PHP using pg_connect command we get an error saying that
"pg_connect() is undefined on line no 10 in main.php".

We are able to start the server but are not able to connect to the
port.Pls anybody help me in getting the script to start the server to
the port.

                            Thanks
                            Arun