<span  id="clock" ></span>

function time() {

            var today = new Date();

            var hou;

            var time;

            var day;

            if (today.getHours() < 12 && today.getHours() >= 0) {

                hou = today.getHours();

                time = "AM";

            } else if (today.getHours() <= 24 && today.getHours() > 12) {

                hou = today.getHours() - 12;

                time = "PM";

            }

            var d = today.getDay();

            if (d == 0) {

                day = "日";

            } else if (d == 1) {

                day = "一";

            } else if (d == 2) {

                day = "二";

            } else if (d == 3) {

                day = "三";

            } else if (d == 4) {

                day = "四";

            } else if (d == 5) {

                day = "五";

            } else if (d == 6) {

                day = "六";

            }

            document.getElementById("clock").innerHTML = (today.getFullYear() + "年" + (today.getMonth() + 1) + "月" + today.getDate() + "日&nbsp;" + hou + ":" + today.getMinutes() + ":" + today.getSeconds() + "&nbsp;" + time + "&nbsp;星期" + day);

        }

        var myTime = setInterval("time()", 1000);