PSQL error connection

Hello.
I wonder if you could help me? When i tried to make a connection to my database
Postgres by TCP/IP the following ocurred:

Warning: Unable to connect to PostgreSQL server: connectDBStart() -- connect()
failed: Connection refused Is the postmaster running (with -i) at 'dionisio'
and accepting connections on TCP/IP port 5432?

My PHP script is:
$conn = pg_connect("host=remote_host
                    dbname=myDB
                    user=username
                    password=pass");

Thanks for your atention and looking forward to hear from you soon,



               Carla Pereira