title: UWP/WinJS: show a html page in a pop-up window
body: <p>I am working on a JavaScript based UWP app. Now I need to dynamically show a html page(with a url) in a pop-up window. 
  I did some search, there is a <a href="https://msdn.microsoft.com/en-us/library/windows/apps/dn904229.aspx" rel="nofollow">ContentDialog</a> I can probably use:</p>
  
  <pre><code>var object = new WinJS.UI.ContentDialog(element, options);
  </code></pre>
  
  <p>but I cannot find any JavaScript sample code for it. I couldn't figure out what should I pass as "element" and how I put the html in ContentDialog. 
  Thanks in advance for any help. </p>