title: Set property value outside Knockout view model definition
body: <p>I have a Knockout view model defined like this:</p>
  
  <pre><code>function viewModel () {
      var self = this;
  
      self.myName = ko.observable();
      self.myValue = ko.observable("10");
  };
  </code></pre>
  
  <p>Now I needed to change a value of the view model when a link was clicked, like this:</p>
  
  <pre><code>$('a.treeitem').live("click", function (e) {
      e.preventDefault();
      viewModel.myValue("20"); // this line does not work
  });
  </code></pre>
  
  <p>However, I can't find out the correct way of setting the value, Chrome console shows the following message:
  <em>Uncaught TypeError: Object function viewModel() { ... } has no method 'myValue'</em></p>