When Login as a user with (example : ramesh) if same user same time can't login
When User close the browser without logout then its should Auto logged out
i will update query as insert status=0 for logout and login status=1
mysql_query("update usermaster set Status=0 where Username='$user' and password='$pass' and Role='$role'");
I have problem need auto logout status change with 0 and if browser closed without logout then also should be update status with 0
Easier way to do that is by using timeout - when user access any page you set status = 1 and last_seen = NOW() and then you can try to assume that if last_seen is more than x time ago so that user leave your site. You can also use ajax to "ping" your server in background to make sure you don't logout him when he is for instance writing long post or something like that.