点击按钮出现60秒倒计时，JS（按钮）

 <script type="text/javascript">
         var countdown=60;
         function settime(val) {
             var e = $('#email').val();
             //对电子邮件的验证
             var myreg = /^([a-zA-Z0-9]+[_|\_|\.]?)*[a-zA-Z0-9]+@([a-zA-Z0-9]+[_|\_|\.]?)*[a-zA-Z0-9]+\.[a-zA-Z]{2,3}$/;
             if(!myreg.test(e))
             {
                 return;
             }
             if (countdown == 0) {
                 val.removeAttribute("disabled");
                 val.value="获取验证码";
                 countdown = 60;
                 return;
             } else {
                 val.setAttribute("disabled", true);
                 val.value="重新发送(" + countdown + ")";
                 countdown--;
             }
             setTimeout(function() {
                 settime(val)
             },1000)
         }
     </script>