JS 显示时间

<div class="GlobalClock">
        <span id="spanClock">clock</span>
 </div> 

.GlobalClock {
    padding: 10px 20px 0 0;
    text-align: right;
    color: Black;
    font-size: 26px;
    font-weight: bold;
}

function startclock() { 

          var thetime = new Date(); 

          //本地时间与GMT时间差距
          //thetime.getTimezoneOffset() / 60;
          //获取GMT时间
          //thetime.getUTCHours();
          //获取GMT时间          
          //(thetime.getHours() + AorP);
          //获取本地时区
          //var tzo = (new Date().getTimezoneOffset() / 60) * (-1);

    var nhours = thetime.getHours();
    var nmins = thetime.getMinutes();
    var nsecn = thetime.getSeconds();
//    var nday = thetime.getDay();
//    var nmonth = thetime.getMonth();
//    var ntoday = thetime.getDate();
//    var nyear = thetime.getYear();
    var AorP = " ";

    if (nhours >= 12)
        AorP = "P.M.";
    else
        AorP = "A.M.";

    if (nhours >= 13)
        nhours -= 12;

    if (nhours == 0)
        nhours = 12;

    if (nsecn < 10)
        nsecn = "0" + nsecn;

    if (nmins < 10)
        nmins = "0" + nmins;

//    if (nday == 0)
//        nday = "Sunday";
//    if (nday == 1)
//        nday = "Monday";
//    if (nday == 2)
//        nday = "Tuesday";
//    if (nday == 3)
//        nday = "Wednesday";
//    if (nday == 4)
//        nday = "Thursday";
//    if (nday == 5)
//        nday = "Friday";
//    if (nday == 6)
//        nday = "Saturday";

//    nmonth += 1;

//    if (nyear <= 99)
//        nyear = "19" + nyear;

//    if ((nyear > 99) && (nyear < 2000))
//        nyear += 1900;

    document.getElementById("spanClock").innerHTML = nhours + ": " + nmins + ": " + nsecn; // + " " + AorP + " " + nday + ", " + nmonth + "/" + ntoday + "/" + nyear;

    setTimeout('startclock()', 1000);

}