How to limit concurrent logins in NT??

For security reasons, I want to ensure that a username CANNOT be used to login to the Domain if someone is already logged in with that username.

If u think of it…it’s a pretty basic need for beefing up security, however there’s no way to do this with NT(Novell has a feature where u can limit the concurrent logins for a pertucular username).

So how can we do this? Think about it guys….it’s really worth it if we could find a technique to do this.

Regards,
Vivek Chudgar