window.onload = function () {
    var show = document.getElementById("show");
    setInterval(function () {
        var time = new Date();
        // 程序计时的月从0开始取值后+1
        var m = time.getMonth() + 1;
        var d = time.getDate();
        var h = time.getHours();
        var mt = time.getMinutes();
        var ms = time.getSeconds();
        if (m < 10) {
            m = '0' + m;
        }
        if (d < 10) {
            d = '0' + d;
        }
        if (h < 10) {
            h = '0' + h;
        }
        if (mt < 10) {
            mt = '0' + mt;
        }
        if (ms < 10) {
            ms = '0' + ms;
        }
        var t = time.getFullYear() + "-" + m + "-" + d + " " + h + ":" + mt + ":" + ms;
        show.innerHTML = t;
    }, 1000);
};