Password Change from one location and Security

Hi, I am creating an asp.net web application with "Remember Me" option during Login and it has an Edit Profile module where users can change their passwords. Here is the scenario. 1. I logged into the website from Machine A clicking "Remember Me". So I am logged in and since a persistent cookie is created I dont need to login the next time until my forms authentication times out. 2. I logged into the website from Machine B using the same account details I used above and from this machine, I changed my password.  In this case How can I make the user in Machine A to login again? (Since my credentials have changed). The same scenario can happen if someone gets any user's credential and uses the application.. Thanks, Vishnu.Y