title: Knockout.js - xxxx is not a function
body: <p>I am trying to incorporate Knockout.js into a WebApplication.</p>
  
  <p>The tutorial I am basing much of my code on is <a href="http://learn.knockoutjs.com/#/?tutorial=webmail">here</a>.</p>
  
  <p>Basically - I have a list of items - I want to be able to click an item and have the corresponding data appear in a div at the bottom of the page. Eventually I'll use jquery.UI Dialog plugin to turn this div into a popup, but for now, I'm just trying to get the selectedItem to work.</p>
  
  <p>My (simplified) code is here: <a href="http://jsfiddle.net/fZXAX/1/">http://jsfiddle.net/fZXAX/1/</a></p>
  
  <blockquote>
    <p>I just get the error:  <em>actionListViewModel.selectedActionId is not a function</em>.</p>
  </blockquote>
  
  <p>I don't see the difference between this and the tutorial which uses selectedMailId in an identical way. The only difference between my code and the example is that I am not using literal notation.</p>
  
  <p>Can anyone see where I am going wrong?
  Thanks in advance.</p>