Help!

I am a complete newbie to PostgreSQL.  I have been using Visual FoxPro for
many years and now need to use a product which can support much larger data
tables so decided to use PostgreSQL.  I am following Rich Blum's book on
PostgreSQL 8 for Windows and have hit a problem.  I have created a schema,
store, and added 3 tables.  I have added two group roles, apparently
successfully, Accountant and Salesman.  I now want to assign privileges to
the tables but when I try I can only see the public role in the roles
dropdown.  I am obviously missing something very simple but can't see it.
Any help will be gratefully received.

TIA

John Weller
01380 723235
07976 393631