var Timer; 
var TotalSeconds;

function CreateTimer(TimerID, Time) {
 
	Timer = document.getElementById(TimerID);
 
       TotalSeconds = Time;
       UpdateTimer()
 
       window.setTimeout("Tick()", 1000);
 
}
 
function Tick() {
	if (TotalSeconds <= 0) {

       	alert("Time's up!");
       	return;
    	}
	TotalSeconds -= 1;
       UpdateTimer()
       window.setTimeout("Tick()", 1000);
}
 
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) ? "<ul><li id='dias'>" + Days + " dia(s)</li>" : "") + "<li id='horas'>" + LeadingZero(Hours) + " hora(s)</li>" + "<li id='minutos'>" + LeadingZero(Minutes) + " minuto(s)</li>" + "<li id='segundos'>" + LeadingZero(Seconds) + " segundo(s)</li><li id='texto-final'></li></ul>";

       Timer.innerHTML = TimeStr;
}

function LeadingZero(Time) {
	return (Time < 10) ? "0" + Time : + Time;
}