title: Jquery .on('change') not firing for dynamically added elements
body: <p>So I've got a page with the following structure</p>
  
  <pre><code>&lt;div class="editCampaignBanner"&gt;
      &lt;div&gt;
      &lt;hr&gt;
      &lt;label for="file"&gt;Upload a new image&lt;/label&gt;
      &lt;input id="file" type="file" name="file" class="valid"&gt;
      &lt;label for="NewImageURLs"&gt;Link URL (Optional)&lt;/label&gt;
      &lt;input id="NewImageURLs" type="text" value="" name="NewImageURLs"&gt;
      &lt;hr&gt;
      &lt;/div&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>and I've written some jquery thus:</p>
  
  <pre><code>$('div.editCampaignBanner input:file').on('change', function () {
          var value = $(this).val();
          var div = $(this).parent();
          var html = '&lt;div&gt;'+ div.html() + '&lt;/div&gt;';
          if (value.length &gt; 0) {
              div.after(html);
          }
          else if ($(this) &gt; 1) {
              div.remove();
          }
      });
  </code></pre>
  
  <p>so when I enter an element into the file it generates a div under the previous one:</p>
  
  <pre><code>    &lt;div class="editCampaignBanner"&gt;
          &lt;div&gt;
          &lt;hr&gt;
          &lt;label for="file"&gt;Upload a new image&lt;/label&gt;
          &lt;input id="file" type="file" name="file" class="valid"&gt;
          &lt;label for="NewImageURLs"&gt;Link URL (Optional)&lt;/label&gt;
          &lt;input id="NewImageURLs" type="text" value="" name="NewImageURLs"&gt;
          &lt;hr&gt;
          &lt;/div&gt;
          &lt;div&gt;
          &lt;hr&gt;
          &lt;label for="file"&gt;Upload a new image&lt;/label&gt;
          &lt;input id="file" type="file" name="file" class="valid"&gt;
          &lt;label for="NewImageURLs"&gt;Link URL (Optional)&lt;/label&gt;
          &lt;input id="NewImageURLs" type="text" value="" name="NewImageURLs"&gt;
          &lt;hr&gt;
          &lt;/div&gt;
      &lt;/div&gt;
  </code></pre>
  
  <p>But now, despite the event being registered using <code>.on()</code> the second file input in the div does not fire the event. What am I missing?</p>