title: popup can't stay in the center of screen due to background page scrolling back to top
body: <p>I have this problem that the page is scrolling to the top when I click a button to open a popup window. </p>
  
  <p>So, if I scroll down the page to almost bottom, there is a button 'submit', when clicked, a popup window will open, which supposed to open in the center of the screen. But once 'submit' is clicked, the page scrolls up to the top, which makes the popup is not visible(the popup window is in the center of the old page before it scrolls to the top). What's more, if I scroll page down, close the popup window, click 'submit' again, the page will not scroll to the top, and the popup is indeed in the center of the window. It's only the first time when the button is clicked, the page will scroll to the top by itself. </p>
  
  <p>I want the popup window keep in the center of the screen all the time, I used <code>data-position-to="window"</code> to achieve this. I believe the reason it's not in the center is because the page itself scrolls to the top. Wondering how should I do to fix this?</p>
  
  <p>This is my popup :</p>
  
  <pre><code>&lt;div data-role="popup" id="feedbackValidationError" data-position-to="window" data-dismissible="false" data-history="false" data-overlay-theme="a" data-transition="slidedown" class="ui-corner-all"&gt;
          &lt;div data-role="header" data-theme="a"&gt;
              &lt;h1 class="center"&gt;Form Error&lt;/h1&gt;
          &lt;/div&gt;
          &lt;div data-role="content" class="ui-corner-bottom ui-content popupPadding"&gt;
              &lt;p&gt;Please answer to at least one of the questions&lt;/p&gt;
              &lt;a href="#" data-role="button" id="feedbackValidationErrorButton"&gt;OK&lt;/a&gt;
          &lt;/div&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>Code I use to open popup:</p>
  
  <pre><code>$("#feedbackValidationError").popup("open");
  </code></pre>
  
  <p>and for close the popup:         </p>
  
  <pre><code> $(document).on('pageinit', '#FeedbackEnter',
       function () {
           $("#feedbackValidationErrorButton").on("click", 
               function () {
                    $("#feedbackValidationError").popup("close");
               }
           );
        }
   );
  </code></pre>