//倒计时 顺手小练习

var time = 180;
t = setInterval(function () {
    time--;
    if (time <= 0) {
        clearInterval(t);
        return;
    }
    Time(time);
}, 1000);
function Time(time) {
    var min = '0' + Math.floor(time / 60);
    $('.min').html(min);
    time = time % 60;
    var ss = Math.floor(time) > 9 ? Math.floor(time) : '0' + Math.floor(time);
    $('.second').html(ss);
}