title: Applying a % style binding with knockout via function not working
body: <p>I want to set the width of a div equal to a percentage calculated by a javascript method.  I can get knockout to apply the style binding properly using this:</p>
  
  <pre><code>&lt;div class="bar" data-bind="style: { width: '50%'}"&gt;&lt;/div&gt;
  </code></pre>
  
  <p>but when I try to use a function to generate the output, it breaks: </p>
  
  <pre><code>&lt;div class="bar" data-bind="style: { width: function(){return '50' + '%';}}"&gt;&lt;/div&gt;
  </code></pre>