html代碼：

<input type="button"  value="獲取驗證碼"  id="getCode" style="color:#4664E6;background:white;" />

Jquery代碼：別忘了引用jquery庫

 <script type="text/javascript">
        var countdown = 60;
        $(function () {
            $("#getCode").bind("click", function () {
                settime();
            });
        })
        function settime(e) {
            
 
if (countdown == 0) {
                countdown = 60;
                $("#getCode").val("獲取驗證碼");
                $("#getCode").removeAttr("disabled");
                return false;
            } else {
                countdown--;
                $("#getCode").val(countdown + "秒後重新獲取");
                $(
 
"#getCode").attr("disabled", "disabled");
            }
            setTimeout(function () {
                settime();
            }, 1000);
        }
    </script>

Jquery驗證碼倒計時