php -postgresql

hi people,
i have been trying to connect to the database using php. but i am not
able to do so .i am getting the following errors




      *Warning*: pg_connect(): Unable to connect to PostgreSQL server:
      FATAL: IDENT authentication failed for user "jay" . in
      */var/www/proj/psql_results.php* on line *37*

on using the following command
 $connection = pg_connect("host=localhost dbname=cs542 user=jay") or
die("could not connect");

 can anyone tell me where am i going wrong.
help would be greatly appreciated
thanks
jay