connection question

Hi all,
I've only used my Pg database on my host machine, and I'm not sure
how to connect from another machine.

DBI connect('database=
dseq_samples;host=littlecatb.ohsu.edu','kellert',...) failed: could
not connect to server: Connection refused
Is the server running on host "littlecatb.ohsu.edu" and
accepting
TCP/IP connections on port 5432?
at /Users/kellert/bin/insert_pwd_record.pls line 16

The server is running on littlecatb, but I don't know if it's
accepting connections. I'm sure this is in the Douglas(s) book and
I'll look it up. ... but if someone knows off the top of their head:
help would be appreciated.
Here's the connection snippet of my script:
use DBI;
my $url = "dbi:Pg:database=dseq_samples;host=littlecatb.ohsu.edu";
my %attrs = ( RaiseError => 1,
PrintError => 0,
AutoCommit => 1,
);
my $username = "kellert";
my $password = "";
my $dbh = DBI->connect($url, $username, $password, \%attrs) or
die "Can't connect to PostgreSQL:
$DBI::errstr (DBI::err)\n";

Tom K