Expire Session When the Browser Close [Codeigniter]

I wanted user to log again to the site whenever they close the browser. i searched everywhere and i found the easiest way.

application/config/config.php

sess_expire_on_close = TRUE

Easy

Session Preferences

You'll find the following Session related preferences in your file:

Preference	Default	Options	Description
sess_cookie_name	ci_session	None	The name you want the session cookie saved as.
sess_expiration	7200	None	The number of seconds you would like the session to last. The default value is 2 hours (7200 seconds). If you would like a non-expiring session set the value to zero: 0
sess_expire_on_close	FALSE	TRUE/FALSE (boolean)	Whether to cause the session to expire automatically when the browser window is closed.
sess_encrypt_cookie	FALSE	TRUE/FALSE (boolean)	Whether to encrypt the session data.
sess_use_database	FALSE	TRUE/FALSE (boolean)	Whether to save the session data to a database. You must create the table before enabling this option.
sess_table_name	ci_sessions	Any valid SQL table name	The name of the session database table.
sess_time_to_update	300	Time in seconds	This options controls how often the session class will regenerate itself and create a new session id.
sess_match_ip	FALSE	TRUE/FALSE (boolean)	Whether to match the user's IP address when reading the session data. Note that some ISPs dynamically changes the IP, so if you want a non-expiring session you will likely set this to FALSE.
sess_match_useragent	TRUE	TRUE/FALSE (boolean)	Whether to match the User Agent when reading the session data.