restrict number of sessions of any particular user id

Hi,

Is there any way around to restrict the number of sessions of any user id?

Suppose "user1" is the user id and it has already have opened two sessions of siebel application. We want to restrict this user to open only two session. Now if this user again tries to open a new session, and if the old sessions are still existing, it either log out the oldest session or prompt that it has reached the maximum number of session.

Thanks,

Abhishek