var imgCount = 8;
var imgPresentation = null;
var timerInterval = 4000;
var timer;

function loaded() {
	imgPresentation = document.images["imgPresentation"];
	if (imgPresentation != null)
		timer = setInterval("changeImage()", timerInterval);
}

function changeImage() {
	clearInterval(timer);
	var i = Math.round(Math.random() * imgCount);;
	if (i < 1)
		i = 1;
	var img = new Image();
	img.src = "img/aktuality/" + (i < 10 ? "0" : "") + i + ".jpg";
	imgPresentation.src = img.src;
	timer = setInterval("changeImage()", timerInterval);
}