How to destroy session with browser closing in codeigniter

Question

Recently I have developed a web application with codeigniter. I am facing a session related problem there badly.

Problem scenario:

If user

Answer 1

Open the general config file application/config/config.php, search for $config[‘sess_expiration’]

change

$config['sess_expiration'] = 7200;

to

$config['sess_expiration'] = -1;