function changeOpac(opacity, id)
{
	var object = document.getElementById(id).style;
	object.opacity = (opacity / 100);
	object.MozOpacity = (opacity / 100);
	object.KhtmlOpacity = (opacity / 100);
	object.filter = "alpha(opacity=" + opacity + ")";
}

function blendimage(divid, imageid, image, millisec)
{
	var speed = Math.round(millisec / 10);
	var timer = 0;

	document.getElementById(divid).style.backgroundImage = "url(" + document.getElementById(imageid).src + ")";

	changeOpac(0, imageid);

	//document.getElementById(imageid).src = image.src;
	swapImage(imageid, image);

	for(i = 0; i <= 100; i++)
	{
		setTimeout("changeOpac(" + i + ",'" + imageid + "')",(timer * speed));
		timer++;
	}
}

var slideCache = new Array();
function RunSlideShow(divid,imageid,displaySecs)
{
	var nextImage = getNextImage();

	if(nextImage != null) {
		changeOpac(0, imageid);
		blendimage(divid,imageid,nextImage,100);
	}

	setTimeout("RunSlideShow('"+divid+"','"+imageid+"',"+displaySecs+")",displaySecs*1000);

}

function getNextImage()
{
	var i;
	var img = null;
	if(slideCache.length > 0) {
		for(i=0;i<slideCache.length;i++) {
			var curr_img = slideCache[i];
			if(curr_img.show) {
				curr_img.show = false;
				var j = i+1;
				if(j > slideCache.length-1) j = 0;
				img = slideCache[j];
				img.show = true;
				break;
			}
		}
		if(img == null) {
			img = slideCache[0];
			img.show = true;
		}
	}
	return img;
}

function swapImage(image_id, nextImg)
{
	var blnDOMSUPPORT = (document.getElementById) ? true : false;

	if ( blnDOMSUPPORT ) {
	   var imgMain = document.getElementById(image_id);
	   var divParent;
 
	   var imgNew = document.createElement('img');

	   imgNew.src = nextImg.src;
	   imgNew.width = 450;
	   imgNew.height = 300; 
	   imgNew.id = image_id;
	   imgNew.style.opacity = 0;
	   imgNew.style.MozOpacity = 0;
	   imgNew.style.KhtmlOpacity = 0;
	   imgNew.style.filter = "alpha(opacity=0)";

	   divParent = imgMain.parentNode;
	   divParent.replaceChild(imgNew, imgMain);

	} else {
 
	   document.images[image_id].src = this.src;
	   alert( 'old school' );

	}   
}

function startimages(imgf)
{
	if(imgf != null) {
		loadXmlDoc(imgf, parseXml);
		RunSlideShow("mainimagearea","mainimage",5);
	}
}

function parseXml(xmlhttp)
{
	var xmlDoc = makeXmlDoc(xmlhttp);
	if(xmlDoc != null) {
		var x = xmlDoc.getElementsByTagName("file");
		var i;
		for(i=0; i<x.length; i++) {
			var im = x[i].childNodes[0].nodeValue;
			var img = new Image;
			img.src = im;
			img.height = 300;
			img.width = 450;
			img.show = false;
			slideCache.push(img);
		}
	}
}