title: Get number of elements inside of an element in xml with jQuery
body: <p>I have this xml file: </p>
  
  <pre><code>&lt;row&gt;
      &lt;question name="faq"&gt;&lt;/question&gt;
      &lt;answer name="faq"&gt;&lt;/answer&gt;
      &lt;question_down name="faq"&gt;&lt;/question_down&gt;
      &lt;answer_down name="faq"&gt;&lt;/answer_down&gt;
      &lt;question_down name="faq"&gt;&lt;/question_down&gt;
      &lt;answer_down name="faq"&gt;&lt;/answer_down&gt;
      &lt;question_down name="faq"&gt;&lt;/question_down&gt;
      &lt;answer_down name="faq"&gt;&lt;/answer_down&gt;
  &lt;/row&gt;
  </code></pre>
  
  <p>I want to know how many <code>&lt;question_down&gt;</code> elements I have inside <code>&lt;row&gt;</code>,
  how can I do this using jQuery or pure javascript?</p>