function countdown(y,m,d,h,i,s,onTick)
{
	var now = new Date();
	var future = new Date(y,m-1,d,h,i,s);
	var diff = future.getTime() - now.getTime();
	diff = Math.floor(diff/1000); // no milliseconds

	now = null;
	future = null;

	if (diff <= 0)
		onTick(0,0,0,0,false);
	else
	{
		var days = Math.floor(diff/86400);
		diff = diff%86400;

		var hours = Math.floor(diff/3600);
		diff = diff%3600;

		var mins = Math.floor(diff/60);
		diff = diff%60;

		var secs = Math.floor(diff);

		onTick(days,hours,mins,secs,true);
		setTimeout(function(){countdown(y,m,d,h,i,s,onTick);}, 1000);
	}
}

function sample_ontick(d,h,m,s,inprogress)
{
	if (inprogress)
		document.getElementById('sample_countdown').innerHTML = d+" nap "+h+" óra "+m+" perc "+s+" másodperc<br>";
	else
		document.getElementById('sample_countdown').innerHTML = 'vége.';
}