Do session cookies expire when the browser is closed?

[illumnFum]

I have a PHP application where I set \[code\]$_SESSION['user']="logged"\[/code\] once a user is authenticated. I call this loginpage.php.Once authenticated and the session variable set, the user is taken to a member page which starts with the lines:\[code\]<?phpsession_set_cookie_params(0,'/');session_start();if($_SESSION['user'] != 'logged') {header ("Location:loginpage.php");}?>\[/code\]When a user has logged in, closes the browser and then visits the members page, I expect him to be redirected to loginpage.php.However, this does not happen. The session cookie is still there in the browser - I tested this using Firefox.Could someone explain to me where I'm getting it wrong?