In your Example you write the following:
"$dbconn3 = pg_Connect ("user=lamb passwd=baaaa dbname=mary ");" 

and later on 

"The arguments available include dbname port, host, tty, options, user, and password ".

The Codeline in your Example won't work with PHP 4.0.2, until you change it into
"$dbconn3 = pg_Connect ("user=lamb password=baaaa dbname=mary ");".

You have to write "password=" instead of "passwd="!

CU
AndiB