Help Conecting to a database from PHP

Hi All!

My PC has Slackware Linux 9.1 installed.

And Apache and PHP are working well....I can make and use the PHP functions in my web pages. Recently I've downloaded
andinstalled PostgreSQL 7.3.2, it seems to work well too, I can make databases, tables and all...But when I try to use
thePHP functions to connect to the database (pg_connect or pg_pconnect) it doesn't work. I've granted select permission
tomy user and nobody user in the table of the databse, and my pg_hba.conf seems to be ok (  localhost        all    all
  trust ). 
The browser even not give any error or something....it just don't work...

I think I'm using the function in the correct way: $conn = pg_connect ("localhost","","","","mydbname");

I've tried too: $conn = pg_connect ("dbname=mydbname");

with and without the port number (5432), and when I type: netstat -nat       it shows:

    0.0.0.0:5432      LISTEN

in the list

I'm starting the database server in this way: /usr/local/pgsql/bin/postmaster -i -D /usr/local/pgsql/data

thanks....

does somebody know what can I do?