Error"Unable to connect to PostgresSQL server: connectDBStart()" - Mailing list pgsql-php

 hello,
         I am using PHP to connect to postgresql server. Till now it was
 working fine and PHP was connecting sql server without any problems.
 Suddenly today i am getting an error or warning which says
 'Warning:
 Unable to connect to PostgresSQL server: connectDBStart() -- unknown
 hostname: localhost in /var/www/html/phpfiles/others/othersbrowse.php on
 line 20
                  Warning: Supplied argument is not a valid PostgreSQL link
 resource in /var/www/html/phpfiles/others/othersbrowse.php on line 25
                                                         ERROR IN
 EXECUTION'


 I am not getting what the problem was. Beform some times it used to come
 but when i restarted the system it used to work fine.
 Pls anybody tell me what the problem is and any suggestions pls since the
 server has to run all the 24 hours and 365 days.
         thanks in advance
               Arun