//find next image
function nextImage(o) {
	do o = o.nextSibling;
	while(o && o.tagName != 'IMG');
	return o;
}
//find first image inside an element
function firstChildImage(o) {
	o = o.firstChild;   
	while(o && o.tagName != 'IMG') {
		o = o.nextSibling;
	}
	return o;
}
//set the opacity of an element to a specified value
function setOpacity(obj, o) {
	obj.style.opacity = (o / 100);
	obj.style.MozOpacity = (o / 100);
	obj.style.KhtmlOpacity = (o / 100);
	obj.style.filter = 'alpha(opacity=' + o + ')';
}
//make image invisible and set next one as current image
function getNextImage(image) {
	if (next = nextImage(image)) {
	image.style.display = 'none';
	image.style.zIndex = 0;
	next.style.display = 'block';
	next.style.zIndex = 100;
	} else {
	//if there is not a next image, get the first image again
	next = firstChildImage(image.parentNode);
	image.style.display = 'none';
	image.style.zIndex = 0;
	}
	return next;
}
//set default values for parameters and starting image
function blendImages(id, speed, pause, caption) {
	if(speed == null) {
		speed = 70;
	}
	if(pause == null) {
		pause = 4000;
	}
	var blend = document.getElementById(id);
	var image = firstChildImage(blend);
	startBlending(image, speed, pause, caption);
}
//make image a block-element and set the caption
function startBlending(image, speed, pause, caption) {
	image.style.display = 'block';
	continueFadeImage(image, 0, speed, pause, caption);
}
// ASC: copied from http://www.sean.co.uk/a/webdesign/javascriptdelay.shtm
function pausecomp(millis) {
	var date = new Date();
	var curDate = null;
	do { curDate = new Date(); }
	while(curDate-date < millis);
} 
//set an increased opacity and check if the image is done blending
function continueFadeImage(image, opacity, speed, pause, caption) {
	opacity = opacity + 3;
	if (opacity < 103) {
	setTimeout(function() {fadeImage(image, opacity, speed, pause, caption)}, speed);
	} else {
	//if the image is done, set it to the background
	image.parentNode.style.backgroundImage = "url("+image.src+")";
	// ASC: pause 1sec here to prevent MSIE image flash ...
	var paws=pause-1000;
	if (paws < 0 ) {
		paws = 0;
	}
	setOpacity(image,0);
	//get the next image and start blending it again
	image = getNextImage(image);
	setTimeout(function() {startBlending(image, speed, pause, caption)}, paws);		
	}
}
//set the opacity to a new value and continue the fading
function fadeImage(image, opacity, speed, pause, caption) {
	setOpacity(image,opacity);
	continueFadeImage(image, opacity, speed, pause, caption);
}