Nice Mootools Building

  $(document.body).adopt(
    (new Element('form', {method: 'post', enctype: 'multipart/form-data', action: '/alter-avatar/' + kind + '/upload'})).adopt(
      (new Element('div')).adopt(
        new Element('input', {'type': 'file', name: 'upload'}),
        new Element('input', {'type': 'submit', value: 'Send Picture'})
      )
    )
  );