//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;
}

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 + ')';
}

function rotateimage(objname, image, opa) {
	var num;
	var container = document.getElementById(objname);
	if(!image) image = firstChildImage(container);
	var nextimage = nextImage(image);
	if(!nextimage) nextimage = firstChildImage(container);
	if(!opa) opa = 0;
	opa = opa + 5;
	
	if(opa == 5) {
		container.style.backgroundImage = "url("+image.src+")";
		image.style.display = 'none';
		setOpacity(nextimage, opa);
		nextimage.style.display = 'block';
		window.setTimeout(function(){ rotateimage(objname, image, opa); }, "150");
	} else if(opa < 100) {
		setOpacity(nextimage, opa);
		window.setTimeout(function(){ rotateimage(objname, image, opa); }, "150");
	} else {
		setOpacity(nextimage, opa);
		window.setTimeout(function() {rotateimage(objname, nextimage);}, 5000);
	}
}