A way to detach the existing session data while making a new one???

Hi! I'm wondering is, is there a way to lose the existing session and existing session data while making a new session id??? I can't use session_destroy() function because it affected IE users, it doesn't affect the non-IE user at all. I got so tired of problems with IE and having it to work properly with the session id, so I decided not to use session_destory(). So, a case situation here is when an IE user closed the browser without logging out. Then later on, fire-up the browser and log in. Problem with this is when I create a new session_id(), it should work but for some reason, a couple of IE users are being affected because the original user did not log out in the first place. So, I decided not to use session_destroy() because of some strange relation between many IEs and the PHP session_id. So, is there a way to detach any existing session data then creating a new session id when logging in??? Thanks!!!