stay online!! system preference?

hey guys, quick question.. is there a way to prevent my macbook from auto logging off from my account? its plugged into power adapter and for those settings i set it so display goes to sleep but hard disks never actually go to sleep... but after i think about an hour, it just logs me off. i want to stay online.. like AIM with an away message on, but i cant stay on for too longgg it disconnects me wen im logged off!! HELP

Apple ->System Preferences->Security->Uncheck log out after blank minutes of activity

you rock. thank you! ... and v for vendetta is one of my fav movies