JDBC: Problems to find the Driverclasses

Hello,

i've installed the postgres database and compiled the jdbc-driver.
After that, i put the driverlocation to my CLASSPATH (It looks like
CLASSPATH=/usr/local/lib/postgresql.jar:....)
when i start java with my programm, then i get a ClassNotFoundException
(during Class.forName("postgres.Driver"))because it couldn't find
postgres.Driver.
What do i wrong?

Thank you
Rolf