How to pass the session from frontend to backend in joomla site

I am in need of using of session to check for login. I set the session at the frontend and now i need to check the same session at backend so as to check for successful login.

Frontend

$session =& JFactory::getSession(); $session->set('username', "abc123");

backend

$sess开发者_StackOverflow社区ion =& JFactory::getSession(); echo $session->get('username');

But its not displaying the session value, plz help me out? If other solution , you can give it too.

You can check in jos_session table whether user is logged in or not. The session data is not shared between frontend and backend. (If you log in frontend and backend with same user, you can see in jos_session table, there are two different session id to same user)