title: How do I call an MVC action on a textbox key up event using json?
body: <p>I've had a look at the other questions on json and either they don't fully answer my question or I'm just not getting it.</p>
  
  <p>What I want to do, from my mvc app, is to call an action in the controller on the keyup event of a textbox.</p>
  
  <p>I want to then pass back the contents of the textbox, do some stuff with the data and then pass back a list of items which can then be added to a dropdown.</p>
  
  <p>I'm completely new to json but [really] want to get stuck into it.</p>