title: Knockout click binding to checkbox prevents jQuery control of value
body: <p>If you've got a checkbox on a form, to which you bind a function on click using Knockout, it appears to override programming control of the checkbox status.</p>
  
  <p>There's a fiddle demonstrating the problem here:
  <a href="http://jsfiddle.net/Y5Zk8/" rel="nofollow">http://jsfiddle.net/Y5Zk8/</a></p>
  
  <p>Code:</p>
  
  <pre><code>&lt;input type="checkbox" id="thisFails" data-bind="click: $root.Fails" /&gt;
  &lt;label for="thisFails"&gt;This Fails&lt;/label&gt;
  
  var SimpleModel = function() {
          this.Fails = function() {
           alert('clicked');
           $('#thisFails').attr('checked', true);
      }
  };
  
  ko.applyBindings(new SimpleModel());
  </code></pre>
  
  <p>Now, I'm well aware that if I return true or false from my function, it'll work. But imagine for a moment that I can't do that (there's reasons for this - it's complicated). Why can't I control the value of the box in JQuery?</p>