Connection error, help..please

Hi!

When I try to connect to my database "dspace",
the following error message occur:

FATAL: database "dspace" does not exist

My PostgreSQL version is, 8.1.3, although the same error
appear no mather what version of psql that I have.
My system is Windows XP Professional Ed.

If someone got any ideas, then please respond to me.
Appreciate your time!

Best Regards,
Christo

PS. I'm a newbie to PostgreSQL.