help with driver info

Hi,
    I am trying to integrate the JDBC3 driver for Postgresql 7.4 in
the java application server that comes standard to the j2ee 1.4 kit.
Now I am not sure how I can tell what the
"vendor-specific class name that implements the DataSource and/or
XADataSource APIs" field should be filled in with?
I am creating a Connection Pool.

Name : jdbc/postgresql
Resource Type : javax.sql.DataSource

Data Source Class Name : <??>  (Dunno what to put in there)

pg74.215.jdbc3.jar (My driver)

Thanks,
Manohar