var _countDowncontainer=0;
var _currentSeconds=0;
var countTimeId;
var countTimeInitId;
function ActivateCountDown(strContainerID, initialValue) {
       if (countTimeId) 
           window.clearTimeout(countTimeId);
       if (countTimeInitId) 
           window.clearTimeout(countTimeInitId);
     

	_countDowncontainer = document.getElementById(strContainerID);
	
	if (!_countDowncontainer) {
		alert("count down error: container does not exist: "+strContainerID+
			"\nmake sure html element with this ID exists");
		return;
	}
	
	SetCountdownText(initialValue);    
        countTimeInitId=window.setTimeout("CountDownTick()", 1000);
}

function CountDownTick() {
	if (_currentSeconds <= 0) {
            return;
	}
	
	SetCountdownText(_currentSeconds-1);
	countTimeId=window.setTimeout("CountDownTick()", 1000);
}

function SetCountdownText(seconds) {
	//store:
	_currentSeconds = seconds;

	//get minutes:
	var minutes=parseInt(seconds/60);
	
	//shrink:
	seconds = (seconds%60);
	
	//get hours:
	var hours=parseInt(minutes/60);
	
	//shrink:
	minutes = (minutes%60);
	
	//build text:
	var strText = AddZero(hours) + ":" + AddZero(minutes) + ":" + AddZero(seconds);
	
	//apply:
	_countDowncontainer.innerHTML = strText;
}

function AddZero(num) {
	return ((num >= 0)&&(num < 10))?"0"+num:num+"";
}