js倒计时

css

<style>
        #CountMsg {
            background-color: #000;
            color: #fff;
        }
    </style>

html

<div id="CountMsg">
        <strong id="RemainS">00</strong>秒
    </div>

js

        <script>
            var overDate = 1000 * 60; //截止时间:为当前计算机时间+3天
            var NowTime = new Date();
            //var EndTime= new Date(2012,06,24,0,0);  //截止时间：为固定时间
            var EndTime = new Date(NowTime.getTime() + overDate);
            function GetRTime() {
                NowTime = new Date();
                var nMS = EndTime.getTime() - NowTime.getTime();
                var nS = Math.floor(nMS / 1000) % 60;
                var nMS = Math.floor(nMS / 100) % 10;
                if (nS >= 0) {
                    document.getElementById("RemainS").innerHTML = nS + "." + nMS;
                } else {
                    document.getElementById("RemainS").innerHTML = "00.0";
                }
                setTimeout("GetRTime()", 100);
            }
            window.onload = function() {
                GetRTime();
            }
        </script>