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 = year + "年" + month + "月" + day + "日 " + hour + ":" + minute + ":" + second + " " + val;
} 
function add_zero(temp)
{
    if(temp<10) return "0" + temp;
    else return temp;
}
setInterval("get_time()", 1000);