[Koha] zebra problem

hi to all i'm installed koha on debian in last steps in zebra when i run sudo -u {KOHA_USER} zebrasrv -f /etc/koha/koha-conf.xml i get sudo: no passwd entry for {KOHA_USER}! what i shall do now . and when i write in my browser localhost:8080 i get apache page it works . any suggestions , help thank's ti all _________________________________________________________________ Connect to the next generation of MSN Messenger  http://imagine-msn.com/messenger/launch80/default.aspx?locale=en-us&source=wlmailtagline