HI
I changed the below things ,

ini_set('session.cookie_lifetime', 0);
ini_set('session.use_only_cookies', 0);
After changing this i clear the browser cookies ,and then login by username and password after login close the browser and again enter to the sites,it asks the username and password .That means session destroyed when the browser closes .It happens only on Internet Explorer ( IE ).But in firefox doesnot happened.

For firefoe browser any chages in settings.php file.

If any know this please help me.

Thanks in advance.

EDIT: Moved to this forum from "News and Announcements" to facilitate getting support.