title: login before processing POST data asp.net
body: <p>I am working on web form ... HTML form that posts data to aspx page , but before the server process post data .. the user should be logged in ... so it has to redirect user to login page if not logged in .  the problem is post data will be lost when redirecting ,the data is huge to be in session (up to 20 mb)</p>
  
  <p>the data are files in base64 form (strings)</p>
  
  <p>so how I keep post data while user login redirection ??</p>