[otrs] Don't seem to have an otrs user

NEWBIE to both OTRS and Linux!! I am trying to run the Cron.sh script but it says to run it as the otrs user. I don't seem to have an otrs user on my Fedora 4 system. I cannot use 'su otrs' I believe OTRS was installed whilst logged in as root. Should I have created an otrs user before installing? Thanks Gordon