Browser Cache issue in codeigniter

I am new in code igniter.I created a login form and a logout section. When i press the logout section, the page will redirect to login section. And when i click the back button in the browser it will show the previous pages.When i click the clear recent history and the choose cache,and then press the back button, it will not show the recent pages.It only shows the login sect开发者_运维百科ion. How to overcome this?Please help me...

In the .htaccess file please add the lines:

<IfModule mod_headers.c>
Header add Cache-Control:  "no-store, no-cache, must-revalidate"
</IfModule>

this .htaccess file should be out side of the application folder. So if you logout your site i.e. if you destroy all the session then no data be stored in the store. So by clicking the back button in the

$this->output->set_header('Pragma: no-cache');
$this->output->set_header('Cache-Control: no-cache, must-revalidate');
$this->output->set_header('Expires: Mon, 26 Jul 1997 05:00:00 GMT');

header()

I would add this

header("Cache-Control: no-cache, must-revalidate"); // HTTP/1.1
header("Expires: Sat, 26 Jul 1997 05:00:00 GMT"); // Date in the past

to the beginning of pages where the user is logged in.