How to create a user with password

> Hi, all:
>
> In the file of pg_hba.conf, I give the following parameter:
>
> TYPE  DATABASE        IP_ADDRESS              MASK           
> AUTH_TYPE             AUTH_ARGUMENT
> Local all                                                    
> password             
> host  all             127.122.122.0           255.255.255.0  
> password     
>
>       Now look what I got:
>
> $su postgres
> bash$psql template1
> $password
>
>       What is the password for user 'postgres' ? How can I
> create one for this user?
>
> bash$createuser dbadmin
> Shall the new user be allowed to create database?(y/n) y
> Shall the new user be allowed to create more new user? (y/n) y
> password: 'dbadminpassword'
> FATAL 1: password authentication failed for user "postgres"
> Createuser: creation of user 'dbadmin' failed
>
>       If I change the config setting to
>
> Local         all                                     trust
>
>       I can login to template1 database and create users and
> databases, but I fail to give a password to a user. Look:
>
> $su postgres
> bash$createuser dbadmin with password 'dbpassword'
>
>       Now it seems the 'dbpasswod' became the created user.
>
> Anybody knows how to create password for 'postgres' ? How to
> create a user with password?
>
>      
> --------------------------------------------
>
> Hong Jin
> h1jin@ucsd.edu
>