title: How do you handle ajax requests when user is not authenticated?
body: <p>How do you handle ajax requests when user is not authenticated? </p>
  
  <p>Someone enters the page, leaves room for an hour, returns, adds comment on the page that goes throuh ajax using jQuery (<code>$.post</code>). Since he is not authenticated, method return RedirectToRoute result (redirects to login page). What do you do with it? How do you handle it on client side and how do you handle it in controller?</p>