7.0 stable + postfix - how to setup chroot?

[Laszlo Nagy]

What I already did:

syslogd_flags="-s -l /var/spool/postfix/var/run/log"   # put into 
/etc/rc.conf

Then I changed "n" to "y" for all lines in 
/usr/local/etc/postfix/master.cf in the "chroot" column.

But I don't know how to create chrooted environment under 
/var/spool/postfix. Is there a command that can create it for me? Or is 
there a manual telling what files I need to copy from my root fs?

Thanks,

   Laszlo