form表單提交頁面不發生跳轉

<form id="registSubmit" enctype="multipart/form-data" action="/dataTable/uploading" method="post" target="form_iframe" onclick="saveReport()">
    上傳文件：<input type="file" id="file" name="file1"/>
    <input type="submit" id="id_submit" name="id_submit" value="上傳"/>
</form>


<iframe id="form_iframe" name="form_iframe" style="display:none;"></iframe>