var fadeInterval = 150; //velocita di fading
var picObjID = "homePagePic";
var overlayObjID = "homePageOverlay";
var isKHTML = navigator.vendor == 'KDE' || ( document.childNodes && !document.all && !navigator.taintEnabled );


function startSlideshow() {
	var picObj = document.getElementById(picObjID);
	if(picObj) {
		var slideshow = document.getElementById("slideshow");
		var overlay = document.createElement("img");
		overlay.id=overlayObjID;
		overlay.style.position="relative";
		overlay.style.top="-46em";
		if(document.all)
			overlay.style.filter="alpha(opacity=0)";
		else {
			if(isKHTML) {
				overlay.style.KhtmlOpacity=0;
				overlay.style.opacity=0;
			} else {
				overlay.style.MozOpacity=0;
			}
		}
		overlay.src=document.getElementById("pic1").src;
		overlay.style.width="0.1em";
		overlay.style.height="0.1em";
		slideshow.appendChild(overlay);
		overlay.style.width="26.8em";
		overlay.style.height="44.2em";
		var numPics = document.getElementById("preloadPageGallery").getElementsByTagName("img").length;
		setTimeout("showNextPic(2,"+numPics+",99)",5000);
	}
}

function showNextPic(picNum,numPics,opacity) {
	var picObj = document.getElementById(picObjID);
	var overlayObj = document.getElementById(overlayObjID);
	if(document.all) {
		picObj.style.filter="alpha(opacity="+opacity+")";
		overlayObj.style.filter="alpha(opacity="+(100-opacity)+")";
	} else {
		if(isKHTML) {
			picObj.style.KhtmlOpacity=opacity/100;
			picObj.style.opacity=opacity/100;
			overlayObj.style.KhtmlOpacity=(100-opacity)/100;
			overlayObj.style.opacity=(100-opacity)/100;
		} else {
			picObj.style.MozOpacity=opacity/100;
			overlayObj.style.MozOpacity=(100-opacity)/100;
		}
	}
	var textObj = document.getElementById("slideshowtext");
	if(opacity > 0) {
		if(textObj && opacity < 50)
			textObj.innerHTML=document.getElementById("pic"+(picNum-1)).getAttribute("alt");
		setTimeout("showNextPic("+picNum+","+numPics+","+(opacity-10)+")",fadeInterval);
	} else {
		
		var origOverlayID = overlayObjID;
		overlayObjID = picObjID;
		picObjID = origOverlayID;                   
		if(picNum < numPics) {
			picObj.src=document.getElementById("pic"+picNum).src;
			setTimeout("showNextPic("+(picNum+1)+","+numPics+",99)",5000);
		} else {                   
			picObj.src=document.getElementById("pic0").src;                   
			
			setTimeout("showNextPic(1,"+numPics+",99)",5000);
		}
	}
}