title: checked data binding is not working for radio buttons in knockout js
body: <pre><code>&lt;div id="distance-filter" data-bind="foreach: model.distance"&gt;
  &lt;p &gt;&lt;input type="radio" value="value" name="distance" data-bind="checked: model.check"&gt; &lt;span data-bind="text:model.check"&gt;&lt;/span&gt;&lt;/p&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>the checked data binding is not working 
  my model is as follows</p>
  
  <pre><code>var model= {    
      filter_list: ko.observableArray([{filter:'restaurant'},{filter:'hospital'},{filter:'atm'},{filter:'cafe'}]),
      fav_list: ko.observableArray([{fav:'Pizzahut'},{fav:'Dominos'},{fav:'Barista'}]),
       distance: ko.observableArray([{value: 500},{value: 1000},{value: 5000},{value: 10000}]),
       check: ko.observable(1000)
  
  };
  </code></pre>