title: How to detect that user open page using BACK button in browser?
body: <p>Idea is to display message, which will infor muser that ajax part of application can wokr incorrectly when he used "back" button.
  Yes, there is a lot of discussions, but no solutions.
  Best from what I found: Store information about last page on server side, and check current page against server info by ajax. 
  But in this way it would be impossible to use 2 browser windows by same user.</p>