I am not sure if this is the right venue for me to ask this question but I haven't found a discussion yet that can shed light to my problem.

Well, it isn't exactly a Perl problem...

Like perhaps having the ability to know if the client has left or his connection has been cut?

Nope. That you can't do. HTTP is stateless. You can provide him a logout link, but you won't know if he just decides to kill his browser.

Do you have any suggestions on how I can handle this?

If the user tries to relogin and already has a session but that session has been idle for X seconds/minutes/hours expire the session and start a new one else display a page saying that there is an active session. (Such a page might ask the user if he wants to expire it or tell him that he must wait.)

-sauoq
"My two cents aren't worth a dime.";