I am using the facebook api to connect my website with facebook. Here is the problem:

Suppose there are 2 users. User A and User B.

Now, User A joins my website and connect with Facebook and allowed the permissions - after some time, User A logged out from my website. On the same computer, another user User B joins my website. But my website does not show him the connect button and he is already connected with the facebook (some how the previous user "User A") facebook get associated with this.

If I put $facebook->destroySession(); this will remove the active access token and my scripts cant use them any more.

please suggest a good way.