function GetClock() {
    var d = new Date();
    var hours = d.getHours();
    var mins = d.getMinutes();
    var secs = d.getSeconds();
    var am_pm;

    if (hours == 0) {
        am_pm = " AM";
        hours = 12;
    } else if (hours < 12) {
        am_pm = " AM";
    } else if (hours == 12) {
        am_pm = " PM";
    } else if (hours > 12) {
        am_pm = " PM";
        hours -= 12;
    }

    if (mins <= 9) {
        mins = "0" + mins;
    }

    if (secs <= 9) {
        secs = "0" + secs;
    }

    document.getElementById('clockbox').innerHTML = hours + ":" + mins + ":" + secs + am_pm;
}

window.onload = function () {
    GetClock();
    setInterval(GetClock, 1000);
}