title: Knockout.js - simple "Hello World" fails
body: <p>I am doing a very simple hello world for knockout js (from <a href="http://goo.gl/lddLl">http://goo.gl/lddLl</a>) : but my code is generating an error I don't understand.</p>
  
  <pre><code>&lt;!DOCTYPE html&gt;
  
  &lt;html lang="en" xmlns="http://www.w3.org/1999/xhtml"&gt;
  &lt;head&gt;
      &lt;title&gt;AJAX Example&lt;/title&gt;
      &lt;script src="../Scripts/jquery-2.0.3.js"&gt;&lt;/script&gt;
      &lt;script src="../Scripts/knockout-3.0.0.debug.js"&gt;&lt;/script&gt;
  
      &lt;script&gt;
  
          // Here's my data model
          var ViewModel = function (first, last) {
              this.firstName = ko.observable(first);
              this.lastName = ko.observable(last);
  
              this.fullName = ko.computed(function () {
                  // Knockout tracks dependencies automatically. It knows that fullName depends on firstName and lastName, because these get called when evaluating fullName.
                  return this.firstName() + " " + this.lastName();
              }, this);
          };
  
          ko.applyBindings(new ViewModel("Planet", "Earth")); // This makes Knockout get to work
  
      &lt;/script&gt;
  &lt;/head&gt;
  &lt;body&gt;
  
      &lt;p&gt;First name: &lt;input data-bind="value: firstName" /&gt;&lt;/p&gt;
      &lt;p&gt;Last name: &lt;input data-bind="value: lastName" /&gt;&lt;/p&gt;
      &lt;h2&gt;Hello, &lt;span data-bind="text: fullName"&gt; &lt;/span&gt;!&lt;/h2&gt;
  
  &lt;/body&gt;
  &lt;/html&gt;
  </code></pre>
  
  <p>the ko.applyBindings call raises the error: </p>
  
  <p>Uncaught TypeError: Cannot read property 'nodeType' of null knockout-3.0.0.debug.js:2439</p>
  
  <p>from the knockout-3.0.0.debug.js code:</p>
  
  <pre><code>// Perf optimisation: Apply bindings only if...
  // (1) We need to store the binding context on this node (because it may differ from the DOM parent node's binding context)
  //     Note that we can't store binding contexts on non-elements (e.g., text nodes), as IE doesn't allow expando properties for those
  // (2) It might have bindings (e.g., it has a data-bind attribute, or it's a marker for a containerless template)
  var isElement = (nodeVerified.nodeType === 1);
  </code></pre>
  
  <p>I'm too ignorant to know what I'm doing incorrectly...</p>