HTML倒计时JS

var intDiff = parseInt($("#examTime").val());//倒计时总秒数

timer(intDiff);

function timer(intDiff){

window.setInterval(function(){
var day=0,
hour=0,
minute=0,
second=0;//时间默认值
if(intDiff > 0){
day = Math.floor(intDiff / (60 * 60 * 24));
hour = Math.floor(intDiff / (60 * 60)) - (day * 24);
minute = Math.floor(intDiff / 60) - (day * 24 * 60) - (hour * 60);
second = Math.floor(intDiff) - (day * 24 * 60 * 60) - (hour * 60 * 60) - (minute * 60);
}
if (minute <= 9) minute = '0' + minute;
if (second <= 9) second = '0' + second;
//$('#day_show').html(day+"天");
//$('#hour_show').html('<s id="h"></s>'+hour+'时');
$('#minute_show').html('<s></s>'+minute+'分');
$('#second_show').html('<s></s>'+second+'秒');
intDiff--;

if(intDiff==0 || intDiff<0) examEnd();
}, 1000);

}