[Driver Manager]Data source name not found, and no default driver specified

I got the abover error when I run isql PostgreSQL-test -v.

Below are the config files

odbc.ini

[PostgreSQL]
Description         = Test to Postgres
Driver              = PostgreSQL
Trace               = Yes
TraceFile           = sql.log
Database            = test
Servername          = localhost
UserName            =
Password            =
Port                = 5432
Protocol            = 6.4
ReadOnly            = No
RowVersioning       = No
ShowSystemTables    = No
ShowOidColumn       = No
FakeOidIndex        = No
ConnSettings        =

odbcinst.ini

[PostgreSQL]
Description    = PostgreSQL driver
Driver    = /usr/lib/unixODBC/libodbcpsql.so.1
Setup    = /usr/lib/unixODBC/libodbcpsqlS.so.1
FileUsage    = 1

Can anyone tell me what this meassage means? I can connect to test
database via Rekall, however, that is not using ODBC.

Art