點擊按鈕出現60秒倒計時，JS（按鈕）

<script type="text/javascript">
        var countdown=60;
        function settime(val) {
            var e = $('#email').val();
            //對電子郵件的驗證
            var myreg = /^([a-zA-Z0-9]+[_|\_|\.]?)*[a-zA-Z0-9]+@([a-zA-Z0-9]+[_|\_|\.]?)*[a-zA-Z0-9]+\.[a-zA-Z]{2,3}$/;
            if(!myreg.test(e))
            {
                return;
            }
            if (countdown == 0) {
                val.removeAttribute("disabled");
                val.value="獲取驗證碼";
                countdown = 60;
                return;
            } else {
                val.setAttribute("disabled", true);
                val.value="重新發送(" + countdown + ")";
                countdown--;
            }
            setTimeout(function() {
                settime(val)
            },1000)
        }
    </script>