pg_connect()

Hi everybody,

Excuse me for my bad english...

I've installed Red hat Linux 8.0, and php 4.2.2, apache 2.0.40 and
postgresql are installed automatically.

Apache and php runs very well (i created a file "test.php" with the
instruction phpinfo() and the information appears very well when i load my
page in my browser, in particular i see the configure command of php
and --with-apxs --with-pgsql=shared take part of it).

In an other php file, i try to connect a postgres database with the command
pg_connect.
And it appears in my browser this error message:
Fatal error: Call to undefined function: pg_connect() ...

the file httpd.conf contents:
LoadModule php4_module modules/libphp4.so

the file php.ini contents:
pgsql.allow_persistent= On

what should i do?

Thanks for any help

Johann