logging out with Session/Cookies

[jae_green]

How do I log someone out when they close there browser or visit another site.

The cookie and session variables still exists when they leave the site, so how do I kill the session?

[juxstapose]

To unregistar specific variables use:
session_unregistrar('your_var');

To end the session you began with session start use:

[juxstapose]

ooops

session destroy();

[shibiny]

 As I know, there is no method to detect whether user click close the browser. so you have to set the session time out value , if time out .the session is disable. 
 The best way to solve you problem is refresh the page just before  the session will be invalid. you set the timeout value little ,if vistor left your page, the session is going to be invalid right now.
                     YangSB