title: Dependent Observable syntax woes
body: <p>My simple 'dependent observable' does not update and when I give it the syntax of a function as the turorials say is required I get a javascript error.  I'm just trying to sum the three observable values.</p>
  
  <p>If I use</p>
  
  <pre><code>&lt;td&gt;${G1 + G2 + G3}&lt;/td&gt;
  </code></pre>
  
  <p>I get a static display: the  does not update when the other input fields change.</p>
  
  <p>If I use the viewModel.Series I get no display of values at all.
  If change viewModel.Series to: this.G1() + this.G2()  I get a javascript error saying G1 is NOT a function.</p>
  
  <pre><code>var initialData = {"DateId":32,"Scores":[{"Alias":"Cap Stocks","G1":129,"G2":123,"G3":222,
  var theScores = initialData.Scores;
  var viewModel = {scores : ko.observableArray(theScores) };
  viewModel.Series = ko.dependentObservable(function() {
      return this.G1 + this.G2 + this.G3;
   }, viewModel);
  $(function () {
  ko.applyBindings(viewModel); }
  </code></pre>
  
  <p>Here is my template binding that at least displays something</p>
  
  <pre><code>&lt;td&gt; ${Alias}&lt;/td&gt;
  &lt;td&gt;&lt;input data-bind="value: G1"/&gt;&lt;/td&gt;
  &lt;td&gt;&lt;input data-bind="value: G2"/&gt;&lt;/td&gt;
  &lt;td&gt;&lt;input data-bind="value: G3"/&gt;&lt;/td&gt;
  &lt;td&gt;${G1 + G2 + G3}&lt;/td&gt; 
  </code></pre>