One user at a Time

Question

I am trying to implement that only one user can login with given credentials.

I check this at the time of login with this code :

MembershipUser objectUser = Membership.GetUser(Login1.UserName);
    if (objectUser != null)
    {
        boolIsAlreadyLoggedIn = objectUser.IsOnline;
    }

This is working fine. I have problem, when a user checked Remember Me. Scenario : 1. If a user logins with Remember Me checked. Close the browser. 2. Now from another machine or another browser login with same credentials. He can login. 3. But if user login from Browser-1/machine-1 again, he can login, since browser have persistent cookie.

Can anybody suggest me how can I resolve this problem??

Thanks in Advance