rails 3 with oracle

Hi all can you please guide me on how to setup a new rails3
application with oracle as the database.
i have tried so many times and havin errors..
I used this command

rails new <app name> --database oracle

it does create the application fine but in the database.yml file i
have something like this

development:
  adapter: oracle
  database: databaseName
  username: User
  password: Secret

in the gemfile i can only use
gem 'activerecord-oracle_enhanced-adapter', '~>1.3.0'
and i think if am to use that gem i have to get the adapter to be

development:
  adapter: oracle_enhanced
  database: databaseName
  username: User
  password: Secret

Please can someone help me with this because if i change it manually
it gives me an error saying wrong adapter..
Thank you
Regards,
bsanneh