Starting PostgreSQL 7.3.4 with Webmin on Mandrake 9.1

I just installed PostgreSQL 7.3.4 (new default install) and setting up
Webmin to be able to administrate it. Postgres is installed to default
location /usr/local/pgsql

My question: what is the correct command for starting PostgreSQL
server with Webmin and for bootup?

from command line (as root) I successfully did it with:
/usr/local/pgsql/bin/postmaster -D /usr/local/pgsql/data

but when I run it with Webmin I get:
Failed to start database server :

"root" execution of the PostgreSQL server is not permitted.

The server must be started under an unprivileged user id to prevent
a possible system security compromise. See the documentation for
more information on how to properly start the server.

in install documentation I have options:
1)/usr/local/pgsql/bin/postmaster -D /usr/local/pgsql/data
and
2)nohup /usr/local/pgsql/bin/postmaster -D /usr/local/pgsql/data \
</dev/null >>server.log 2>&1 </dev/null &

the second one didn't work from command line either for me.

I also tried with:
/etc/rc.d/init.d/postgresql start
I get No such file or directory.

What is the correct way to do it?

also, I would be glad to read what is the command for starting
Postgres in bootup. can I use the same command?

thanks for all ideas.