Problem after changing the port number of postgres

Hi,

   I have changed the default port of postgres in file "postgresql.conf"
from 5432 to another four digit port which was not assigned to any one
else. After the change I restarted the postgres as well as the system.
But after changing the port while connecting to postgres I am getting
this error:

root@s14-apps:/opt/PostgresPlus/8.4SS# bin/psql -Upostgres
psql: could not connect to server: No such file or directory
       Is the server running locally and accepting
       connections on Unix domain socket "/tmp/.s.PGSQL.5432"?

I checked the path /temp/
the .s.PGSQL.____ file is available there for the new port.

Any help is appreciated.

Thanks & Regards
Himanshu Joshi