I would like to know how to delete and not allow a guest account on my system.

Code:
julio@julio-ThinkCentre-M52:~$ users
julio julio
julio@julio-ThinkCentre-M52:~$
i was able to find the topic for 11.10 but not for 10.10

also when i booted my computer apparmor gave me a debug error message:



Any help would be most welcome, thanks