title: Click every button with the same class on facebook
body: <p>I'm trying to play around with a Facebook group chat I made a while ago. The plain fact is I added too many people and I need to remove absolutely everyone. 
  This is the html of one of the buttons (they all share the same class):</p>
  
  <pre><code>&lt;a class="_42ft _4jy0 _4jy3 _517h _51sy" role="button" href="#" ajaxify="/chat/remove_participants/?elem_id=u_32_4&amp;amp;uid=1124361845&amp;amp;tid=958151054268315" rel="async-post"&gt;Remove&lt;/a&gt;
  </code></pre>
  
  <p>So with that, I hoped to use this here and it'd click all the buttons at once:</p>
  
  <pre><code> document.getElementById('_42ft _4jy0 _4jy3 _517h _51sy').click();
  </code></pre>
  
  <p>But the error message...: </p>
  
  <pre><code>VM1719:1 Uncaught TypeError: Cannot read property 'click' of null(…)
  </code></pre>
  
  <p>comes up.. I'm really confused as to why the click function doesn't work.</p>
  
  <p>Cheers</p>