JS+HTML5实现获取手机验证码倒计时按钮

 <input type="button" value="获取验证码"> 

 input[type=button]
 width: 150px;
 height: 30px;
 background-color: #ff3000;
 border: 0;
 border-radius: 15px;
 color: #fff;
 }
 input[type=button].on {
 background-color: #eee;
 color: #ccc;
 cursor: not-allowed;
 }

 $("input[type='button']").click(btnCheck);
 /**
 * [btnCheck 按钮倒计时常用于获取手机短信验证码]
 */
 function btnCheck() {
 $(this).addClass("on");
 var time = 5;
 $(this).attr("disabled", true);
 var timer = setInterval(function() {
 if (time == 0) {
 clearInterval(timer);
 $("input").attr("disabled", false);
 $("input").val("获取验证码");
 $("input").removeClass("on");
 } else {
 $('input').val(time + "秒");
 time--;
 }
 }, 1000);
 }