title: Knockout.js binding with writeable computed property
body: <p>html: (generated my knockoutmvc)</p>
  
  <pre><code>&lt;select class="span12" data-bind="options : VehicleManufacturers,optionsText : function(item) { return item.Name; },optionsCaption : 'Select Manufacturer...',value : VehicleManufacturer"
  id="VehicleManufacturer"&gt;
      &lt;option value=""&gt;Select Manufacturer...&lt;/option&gt;
      &lt;option value=""&gt;AUDI&lt;/option&gt;
  &lt;/select&gt;
  &lt;span data-bind="with: VehicleManufacturer"&gt;
      &lt;span data-bind="text: Name"&gt;&lt;/span&gt;
  &lt;/span&gt;
  </code></pre>
  
  <p>script:</p>
  
  <pre><code>var viewModelJs = {
       "VehicleManufacturers": [{
           "Id": 5,
           "Name": "AUDI"
       }],
       "VehicleManufacturer": null
   };
   var viewModel = ko.mapping.fromJS(viewModelJs);
   ko.applyBindings(viewModel);
  
  viewModel.VehicleManufacturer = ko.computed({
      read: function () {
          return viewModel.VehicleManufacturer;
      },
      write: function (manufacturer) {
          // Populate Model list routine
      },
      owner: viewModel
  });
  </code></pre>
  
  <p>JsFiddle: <a href="http://jsfiddle.net/ryDjs/2/" rel="nofollow">http://jsfiddle.net/ryDjs/2/</a></p>
  
  <p>I may not bed doing the binding quite right, what I'm trying to achive is drop-down cascade as per <a href="http://marcofranssen.azurewebsites.net/knockout-that-cascading-dropdown/" rel="nofollow">this article</a>, which is working with the code above, except the <code>"with: VehicleManufacturer"</code> binding, i.e. the name of selected manufacturer isn't shown.</p>