title: Different behavior pop-up window css
body: <p>Code below works good on local computer, but on remote server pop-up window doesn't consider scroll width and appears on the top of the page even when i scrolled the page up to the bottom. Problem appears only in IE and only on remote server. Files are the same. What should I check?</p>
  
  <p>HTML</p>
  
  <pre><code>&lt;div style="position:absolute;"&gt;
      &lt;div id="a_div"&gt;
          123
       &lt;/div&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>CSS</p>
  
  <pre><code>#a_div {
      display:none;
      position:fixed;
      width:850px;
      top:35px;
      border:1px solid #B1B8C7;
      background:white;
      z-index:3000;
  }
  </code></pre>
  
  <p>JS</p>
  
  <pre><code>function showaDiv() {
      var div = document.getElementById('a_div');
      var width = document.body.clientWidth;
      if (div) {
          div.style.left = Math.round((width-850)/2)+'px';
          div.style.display = 'block';
          document.getElementById('a_bgdiv').style.display = 'block';
      }    
  }
  </code></pre>