problem with initlocation

i want to make database in another place and i'm unable to use
initlocation, and i don't know, what i'm doing wrong.

this is what i do, and i think it's correct.

www:/home/db/postgres$ su postgres
postgres@www:/home/db/postgres$ ls -l
total 12
drwx------  6 postgres postgres 4096 Aug 31 14:59 data
drwxr-xr-x  2 postgres postgres 4096 Aug 31 14:19 data-web
drwx------  3 postgres postgres 4096 Oct 15  2004 dumpall
postgres@www:/home/db/postgres$ /usr/lib/postgresql/bin/initlocation
/home/db/postgres/data-web/
initlocation: cannot be run as root
Please log in (using, e.g., "su") as the (unprivileged) user that will
own the server process.
postgres@www:/home/db/postgres$

postgres server runs under user postgres
postgres@www:/home/web/holandsko# ps uxaw |grep post
postgres 11006  0.0  0.0 17088 1292 ?        S    Jun29   7:16
/usr/lib/postgresql/bin/postmaster -D /var/lib/postgres/data
postgres 11012  0.0  0.1  7888 2668 ?        S    Jun29  11:22 postgres:
stats buffer process
postgres 11013  0.0  0.1  7944 2500 ?        S    Jun29  10:09 postgres:
stats collector process
postgres 11029  0.0  0.1 12780 3116 ?        Ss   Jun29  17:58
/usr/lib/postgresql/bin/pg_autovacuum -D -p 5432 -L
/var/log/postgresql/autovacuum_log

and info about system
Debian Sarge, kernel 2.4.32, postgresql version 7.4.7

thanks
Josef Micka