title: Custom Facebook share button does not work
body: <p>Can somebody explain why my custom Facebook share button does not work?
  Whenever I click the button it the share window just does not show up. 
  I've tried it as html file on an actual webserver, and I've read everything in the facebook docs regarding the share button. </p>
  
  <p>When using the <a href="http://www.fbrell.com/saved/2779dc018c325d85d650a3b723239650" rel="nofollow noreferrer">same code provided by facebook</a> it does work. </p>
  
  <p>I do get <a href="http://prntscr.com/iqovjp" rel="nofollow noreferrer">this error</a> though when clicking on the button. </p>
  
  <p>This is my code. (Without the CSS because its a bit more, If you need it I can add it.)</p>
  
  <pre><code>&lt;script type="text/javascript" src="https://connect.facebook.net/en_US/sdk.js#xfbml=1"&gt;&lt;/script&gt;
  
  &lt;div class="page-header"&gt;
    &lt;h1&gt;Share Dialog&lt;/h1&gt;
  &lt;/div&gt;
  &lt;p&gt;Click the button below to trigger a Share Dialog&lt;/p&gt;
  &lt;button class="fill" id="fb-share-button"&gt;Share on Facebook&lt;/button&gt;
  
  &lt;script&gt;
  document.getElementById('fb-share-button').onclick = function() {
    FB.ui({
      method: 'share',
      display: 'popup',
      href: 'https://nureinberg.de',
    }, function(response){});
  }
  &lt;/script&gt;
  </code></pre>