function get_time()
    {
        var date=new Date();
        var year="",month="",day="",week="",hour="",minute="",second="";
        year=date.getYear();
        month=add_zero(date.getMonth()+1);
        day=add_zero(date.getDate());
        week=date.getDay();
        switch (date.getDay()) {
        case 0:val="星期天";break
        case 1:val="星期一";break
        case 2:val="星期二";break
        case 3:val="星期三";break
        case 4:val="星期四";break
        case 5:val="星期五";break
        case 6:val="星期六";break
          }
        hour=add_zero(date.getHours());
        minute=add_zero(date.getMinutes());
        second=add_zero(date.getSeconds());
        timetable.innerText="今天是: "+year+"/"+month+"/"+day+" "+val+" "+hour+":"+minute+":"+second;
    }

    function add_zero(temp)
    {
        if(temp<10) return "0"+temp;
        else return temp;
    }
    setInterval("get_time()",1000);