title: Success messages as opposed to model state error messages
body: <p>For error messages, validation faults etc you have </p>
  
  <pre><code>ModelState.AddErrorMessage("Fool!");
  </code></pre>
  
  <p>But, where do you put success responses like "You successfully transfered alot of money to your ex." + "Your balance is now zero". I still want to set it at the controller level and preferably in key-value way, the same way as errormessages but without invalidating the modelstate.</p>
  
  <p>How is this usually done? ViewData?</p>