jquery 实现 点击按钮后倒计时效果,多用于实现发送手机验证码、邮箱验证码

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<script src="www.niyuewo.com/js/jquery-1.4.1.min.js" type="text/javascript"></script>
<script type="text/javascript">

var InterValObj; //timer变量,控制时间
var count = 5; //间隔函数,1秒执行
var curCount;//当前剩余秒数

function sendMessage() {
   curCount = count;
  //设置button效果,开始计时
     $("#btnSendCode").attr("disabled", "true");
     $("#btnSendCode").val("请在" + curCount + "秒内输入验证码");
     InterValObj = window.setInterval(SetRemainTime, 1000); //启动计时器,1秒执行一次
    //向后台发送处理数据
     $.ajax({
       type: "POST", //用POST方式传输
       dataType: "text", //数据格式:JSON
       url: 'www.yiyaojing.com', //目标地址
       data: "dealType=" + dealType +"&u&code=" + code,
       error: function (XMLHttpRequest, textStatus, errorThrown) { },
       success: function (msg){ }
     });
}

//timer处理函数
function SetRemainTime() {
            if (curCount == 0) {                
                window.clearInterval(InterValObj);//停止计时器
                $("#btnSendCode").removeAttr("disabled");//启用按钮
                $("#btnSendCode").val("重新发送验证码");
            }
            else {
                curCount--;
                $("#btnSendCode").val("请在" + curCount + "秒内输入验证码");
            }
        }
</script>
</head>
<body>
        <input  type="button" value="发送验证码" onclick="sendMessage()" /></p>
</body>
</html>