preventing multiple logins

[Sameer]

one important problem i am facing is that my web solution
(asp.net) will be deployed on a webfarm. I am using sql
server session management on clustered sqlservers. but as
i need to prevent multiple logins through a
username/password (same credentials at a time) on the
website.

also session_end() event does not fire in sql server mode.

Regards
Sameer