div class="form-item" id="file-demo-wrapper">
 label for="file-demo">请选择文件:www.jb51.net /label>
 input type="file" name="files[file-demo]"  class="form-file" id="file-demo" size="40" />
/div>




$("#file-demo").remove();
//https://www.jb51.net
$("input type=\"file\" name=\"files[file-demo]\"  class=\"form-file\" id=\"file-demo\" size=\"40\" />").appendTo("#file-demo-wrapper");