There is more simple approach to log out user once session expired.
I think you are confusing between an ASP.NET session and the authentication cookie. I suspect that you are talking about the authentication cookie expiration here. If you have set slidingExpiration to true in your web.
Config then polling AJAX requests will renew the timeout so they are not suitable. Phil Haack described a very elegant way to detect authentication cookie expiration in AJAX calls in this blog post.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.