title: How to position popup at top of screen or fixed at top in jquery mobile?
body: <p>I have a popup in jquery mobile</p>
  
  <pre><code>&lt;div data-role="popup"   id="itemDetails"&gt;
  ...
  &lt;/div&gt;
  </code></pre>
  
  <p>and I call programmatically to open with: </p>
  
  <p><code>$('#itemDetails').popup('open');</code> </p>
  
  <p>, but always open centered in <code>x,y</code> on screen, and I want show fix to top <code>(y=0)</code> of screen, and fixed when I have scroll.</p>
  
  <p>How I can do it?, Thanks in advance.</p>