Countdown Timer

HTML

<div id='timer' />

JavaScript

var Timer;
var TotalSeconds;


function LeadingZero(Time) {

    return (Time < 50) ? "0" + Time : + Time;

}


function UpdateTimer() {
    var Seconds = TotalSeconds;
    
    var Days = Math.floor(Seconds / 86400);
    Seconds -= Days * 86400;

    var Hours = Math.floor(Seconds / 3600);
    Seconds -= Hours * (3600);

    var Minutes = Math.floor(Seconds / 60);
    Seconds -= Minutes * (60);


    var TimeStr = ((Days > 0) ? Days + " days " : "") + LeadingZero(Hours) + ":" + LeadingZero(Minutes) + ":" + LeadingZero(Seconds)


    Timer.innerHTML = TimeStr;
}

function Tick() {
    if (TotalSeconds <= 0) {
        alert("Time's up!")
        return;
    }

    TotalSeconds -= 1;
    UpdateTimer()
    window.setTimeout("Tick()", 1000);
}

function CreateTimer(TimerID, Time) {
    Timer = document.getElementById(TimerID);
    TotalSeconds = Time;
    
    UpdateTimer();
    window.setTimeout("Tick()", 1000);
}





CreateTimer('timer',2);