Unable to reset the password of users in postgres Evrytime i run, su - postgres it asks me for a password which I did not set. I simply installed the postgres. I have gone to the pg_hba.conf.

# Database administrative login by Unix domain socket
local   all             postgres                               trust

# TYPE  DATABASE    USER        CIDR-ADDRESS          METHOD

# "local" is for Unix domain socket connections only
local   all         all                               ident
# IPv4 local connections:
host    all         all         127.0.0.1/32          md5
# IPv6 local connections:
host    all         all         ::1/128               md5


I changed the postgres method from ident to trust and then ran sudo /etc/init.d/postgresql restart. Even then it continues to ask for password. i am not sure where am I going wrong?

What should I do?
I was finally able to solve the issue thanks to this site,

http://scratching.psybermonkey.net/2009/06/postgresql-how-to-reset-user-name.html