function setOpacityAnim(objId, opacity_delta, opacity_end, status){
	obj=document.getElementById(objId);
	opacity_start=obj.style.opacity*100;
	// IE/Win
	obj.style.filter = "alpha(opacity:"+(opacity_start + opacity_delta)+")";
	// Safari 1.2, newer Firefox and Mozilla, CSS3
	obj.style.opacity = (opacity_start + opacity_delta)/100;
	if(opacity_start<opacity_end && status=="hidden"){
		setTimeout("setOpacityAnim('"+objId+"', "+opacity_delta+", "+opacity_end+", '"+status+"')",20);
	}
	if(opacity_start>opacity_end && status=="hidden"){
		setOpacity(objId, opacity_end);
	}
	if(opacity_start>opacity_end && status=="visible"){
		setTimeout("setOpacityAnim('"+objId+"', "+opacity_delta+", "+opacity_end+", '"+status+"')",20);
	}
	if(opacity_start<opacity_end && status=="visible"){
		setOpacity(objId, opacity_end);
	}
}

function setOpacityAnimInit(objId, opacity_end, timeAnim){
	var status="";
	obj=document.getElementById(objId);
	opacity_start = obj.style.opacity*100;
	opacity_delta= Math.round((opacity_end-opacity_start)*100/(timeAnim/20))/100;
	if(opacity_start<opacity_end){
		status="hidden";
	}else{
		status="visible";
	}
	setTimeout("setOpacityAnim('"+objId+"', "+opacity_delta+", "+opacity_end+", '"+status+"')",20);
}
/*Gallery OnBlack*/
function changeImg(objId, urlImg){
	obj=document.getElementById(objId);
	obj.innerHTML = "<img src='"+urlImg+"' />";
}

function changeButton(urlImg, numImg, numMax){
	var backButton="";
	var forwardButton="";
	if (numImg > 0) {
		backButton = "<a onclick='changeImgOnBlack(\""+urlImg+"\", "+(numImg-1)+", "+numMax+", 0)'><img src='img/shared/backBlack.png' /></a>";
	}
	if (numImg < numMax) {
		forwardButton = "<a onclick='changeImgOnBlack(\""+urlImg+"\", "+(numImg+1)+", "+numMax+", 0)'><img src='img/shared/forwardBlack.png' /></a>";
	}
	document.getElementById('backBlack').innerHTML = backButton;
	document.getElementById('backBlack').style.display="inline";
	document.getElementById('forwardBlack').innerHTML = forwardButton;
	document.getElementById('forwardBlack').style.display="inline";
}

function showImgOnBlack(urlImg){
	setDisplay('bgAllGrey', 'inline');
	setDisplay('borderImgOnBlack', 'inline');
	changeImg('imgOnBlack', urlImg);
	document.getElementById('imgOnBlack').style.margin="10px 10px 10px 10px";
	setOpacityAnimInit('borderImgOnBlack', 100, 300, 'hidden');
}

function hideImgOnBlack(){
	setOpacityAnimInit('borderImgOnBlack', 0, 100);
	setTimeout("setDisplay('bgAllGrey', 'none')",100);
	setTimeout("setDisplay('borderImgOnBlack', 'none')",100);
}

function changeImgOnBlack(urlImg, numImg, numMax, step){
	if (step == 0) { /*Il div sparisce*/
		setOpacityAnimInit('borderImgOnBlack', 0, 100);
		changeImgOnBlack(urlImg, numImg, numMax, 1);
	}
	if(step==1){ /*cambio immagine e link*/
		if(document.getElementById('borderImgOnBlack').style.opacity!=0){
			setTimeout("changeImgOnBlack('"+urlImg+"', "+numImg+", "+numMax+",1)", 20);
		}else{
			changeImg('imgOnBlack', urlImg+numImg+".jpg"); /*Attenzione! L'id specificato è quello del tag div che CONTIENE il tag img*/
			urlImgBack="";
			urlImgForward="";	
			if (numImg>0){
				urlImgBack=urlImg+(numImg-1)+".jpg";
			}
			if(numImg<numMax){
				urlImgForward=urlImg+(numImg+1)+".jpg";
			}
			changeButton(urlImg, numImg, numMax);
			changeImgOnBlack(urlImg, numImg, numMax, 2);
		}
	}
	if(step==2){ /*mostro l'immagine*/
		setOpacityAnimInit('borderImgOnBlack', 100, 300);
	}
}