How to enable console cheats black ops ^^

Hi guys,
how to enable the console cheats in black ops?
how to put them on?
When i use /god or /noclip something like that, a msg comes up saying
Cheats are not enabled or something like that?
so how to enable them?
is this possible from console?
i tried sv_cheats 1 or sv_cheat 1 and a lot of other things but not working.
What command do I need?
ty guys

load the map with /devmap