I need to display a list of users currently logged into my system. Is there a more reliable way than to just log the users in a table when they log in? If I use this, then I won't know if the person is actively in the system (they may have logged in and then closed their browser) and they might not use the logout functionality in order to update the log of users in the system. I'm assuming there's a logical way but I don't even know where to start. Would love to hear your thoughts!