The system doesn't maintain your login on it. It's maintained on a persisted Cookie on your machine. If you log out, it sets that cookie to "Logged out" You can also "log out" by deleteing the cookie from your PC.
Yes, Ashik. That is very important now. Always remember to logout when using public computers. Closing all the Browser windows doesnot log you out, atleast on my machine. It is your responsibility to logout correctly. Pauline, Thanks for bring this up. Nice work. - satya