Problems with Oracle dB oci8 connectivity

Hello,
I need to connect from my Windows server over to an Oracle database in
Unix land. I finally got the Oracle client loaded on my server, and, I
downloaded and installed the oci8 gem from rubyforge.

Here’s the top of my script.

require ‘oci8’
require ‘dbi’

begin

connect to the Oracle server

dbh = DBI.connect(“DBI:Oracle:graphicsdb-prod.bna.com/grpprod.bna.com”,
“user”, “password”)

I get the following error:

    "Unable to load driver 'Oracle.'"

I’d appreciate any help on this.

Thanks.