title: Implementing a CAPTCHA in mvc 3.0 and latter
body: <p>I used captcha in mvc 4.0 application and my reference : <a href="http://coderjournal.com/2008/03/aspnet-mvc-captcha/" rel="noreferrer">Asp.Net MVC CAPTCHA</a> </p>
  
  <p>but it implements base on mvc 2.0 it shows an image but in the controller I don't have any OnPreAction method I replace it with OnAuctionExcuting but there is no MethodInfo in it. how I can update code to run on mvc 3.0 or 4.0 ?</p>