페이지 이동없이 submit처리

<script>

  function submit_form() {

    document.frm.target = 'ifrm';

    document.frm.action = 'save_data.php';

    document.frm.submit();

  }

</script>

<form method='post' name='frm'>

  <input type=text name=text_data>

  <input type=button value='submit' onclick='submit_form()'>

</form>

<iframe name='ifrm' width='0' height='0' frameborder='0'></iframe>