jQuery提交form表單

<form id="search_form" name="search_form" method="post">
      <input type="text" name="username" />
</form>

<script type="text/javascript">
    $(function() {
        $('#btn').bind('click', function() {
            document.search_form.action = 'admin/queryAll.do?pid=' + pid;  //定義 action,並傳參
            $('#search_form').submit();
        });
    })
</script>