function getTwoDigitsForm(val)
{
    if (val<10) return "0" + val;
    else return val;
}

function updateTime()
{    
    seconds++;
    if (seconds==60) {minutes++; seconds=0;}
    if (minutes==60) {hours++; minutes=0;}
    if (hours==24) hours=0;
    document.getElementById("hour_str").innerHTML = inittimeStr + getTwoDigitsForm(hours);
    document.getElementById("minute_str").innerHTML = getTwoDigitsForm(minutes);

    var blink = document.getElementById("blinker");
    blink.style.visibility = blink.style.visibility == "" ? "hidden" : "" 
}

updateTime();
window.setInterval(updateTime, 1000);