function init_slideshow(){
	var divArray = document.getElementsByTagName("div");
	var i =0;
	
	for(i=0;i<divArray.length;i++){
		if(divArray[i].className=="slideshow") setSlideshow(divArray[i].id);	
	}
}

function setSlideshow(id){
	var box = document.getElementById(id);
	var imgArray = 	box.getElementsByTagName("div");
	var i = 0;
	
	for(i=0;i<imgArray.length;i++){
		var opacity = (i==0) ? 100 : 0;
		var object = document.getElementById(imgArray[i].id).style; 
		object.opacity = (opacity / 100); 
		object.MozOpacity = (opacity / 100); 
		object.KhtmlOpacity = (opacity / 100); 
		object.filter = "alpha(opacity=" + opacity + ")";
		if(i==0) object.display = "block";
	}
	
	startSlideshow(id,0);
}

function startSlideshow(id,currentSlide){
	var box = document.getElementById(id);
	var imgArray = 	box.getElementsByTagName("div");
	var i = 0;
	var nextSlide = currentSlide+1;
	nextSlide = (currentSlide>=imgArray.length-1) ? 0 : nextSlide;
	
	opacity(imgArray[currentSlide].id,100,0,2000);
	opacity(imgArray[nextSlide].id,0,100,2000);
	
	switch(id){
		case "ss_keurmerken":	var time = 30000;
								break;
		case "ss_slideshow":	var time = 10000;
								break;
		case "ss_feest":		var time = 4000;
								break;
		default:				var time = 10000;
								break;
	}
	
	setTimeout("startSlideshow('"+id+"',"+nextSlide+")",time);
	
}

function opacity(id, opacStart, opacEnd, millisec) { 
	//speed for each frame 
	var speed = Math.round(millisec / 100); 
	var timer = 0; 

	//determine the direction for the blending, if start and end are the same nothing happens 
	if(opacStart > opacEnd) { 
		for(i = opacStart; i >= opacEnd; i--) { 
			setTimeout("changeOpac(" + i + ",'" + id + "')",(timer * speed)); 
			timer++; 
		} 
	} else if(opacStart < opacEnd) { 
		for(i = opacStart; i <= opacEnd; i++) 
			{ 
			setTimeout("changeOpac(" + i + ",'" + id + "')",(timer * speed)); 
			timer++; 
		} 
	} 
} 
			
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 + ")";
	
	if(opacity>0) object.display = "block";
	if(opacity==0) object.display = "none";
}

window.onload = init_slideshow;