iframe upload

html:

<form method='POST' enctype='multipart/form-data' target='upload_iframe' class='common-note-form new_note' accept-charset="UTF-8" action='http://localhost/boss/profile/issue/js/upload_file";'>
    <textarea id='comment' name='comment' class='note_text form-control' rows='5'></textarea>
    <div class="note-form-actions">
       <div class="buttons">
          <input type="hidden" value="15" name='issue_id'>
          <input id='submitcom' class='btn btn-primary comment-btn btn-grouped js-comment-button' type='submit' value='发表评论'>
       </div>
       <div class="note-form-option pull-left">
          <a class="choose-btn btn js-choose-note-attachment-button btn-default">

             <span>选择文件...</span>
          </a>
         &nbsp;<span class="file_name js-attachment-filename">文件名</span>
        <input class="js-note-attachment-input hidden" id="note_attachment" name="files[note]" type="file">
       </div>
    </div>
</form>
<iframe name='upload_iframe' class='hide'></iframe>

####js:

// 点击上传文件按钮，触发input file空间
$('.choose-btn').on('click', function() {
  var target;
  return target = $(this).closest('form'),
  target.find('.js-note-attachment-input').click();
});
// file空间变化事件
$('.js-note-attachment-input').on('change', function() {
  var ele = $(this).closest('form');
  var file_name = $(this).val().replace(/^.*[\\\/]/, "");
  ele.find('.js-attachment-filename').text(file_name);
  return false;
});
//发表评论
$('#submitcom').on('click', function() {
    $(this).closest('form').submit();
    var comment = $('#comment').val();
    if(!comment.length) {
      $.show_message('评论内容不能为空！');
      return false;
    } else {
      $(this).closet('form').submit();
  }
  return false;
});