title: jQuery auto upload file
body: <p>I want the file input will automatic upload my image without enter any submit button.</p>
  
  <pre><code>&lt;form action="/upload/" method="post" enctype="multipart/form-data"&gt;
    &lt;input type="hidden" name="user_id" value="47" /&gt;
    &lt;input type="file" name="upload" /&gt;
  &lt;/form&gt;
  </code></pre>
  
  <p>Let me know the trick with jQuery</p>