function clock()
{
    var hr = "", dt = new Date();
    var miliss = "milliseconds_server".getValue().toDate().getTime();
    setInterval( 
        function()
        {
            miliss += 1000;
            dt.setTime(miliss);
            var h = dt.getHours();
            var m = dt.getMinutes()
            var s = dt.getSeconds();
            hr = (h<10 ? "0"+h : h) + ":" + (m<10 ? "0"+m : m) + ":" + (s<10 ? "0"+s : s);
            "label_hours".setValue(hr);
        },
        1000
    );
}