Sir, as I pointed higher, if you just close your browser, "garbage collector" which run with cronjob only, will logout you only after 30 minutes of inactivity. As I understand, you want to logout user immediately, when he closed his browser. But, how the system can detect that he closed his browser?
P.S.
Quote from idea
You have selected as "lohana" but you should have to select as "other" anyway let's talk on topic
Sorry, but not sure what are you talking about.