var random_display = 0;

var num_slideshows = 3;
var interval = 5000;
var imageDir = "/images/homepage/"; //image path 

var imageNum = 0;
	imageArray = new Array();	

	//Legacy 
	imageArray[imageNum++] = new imageItem(imageDir + "tele_basics.png");
	imageArray[imageNum++] = new imageItem(imageDir + "tele_fund.png");
	imageArray[imageNum++] = new imageItem(imageDir + "ATM.png");
	imageArray[imageNum++] = new imageItem(imageDir + "dwdm.png");
	//IP
	imageArray[imageNum++] = new imageItem(imageDir + "ip_data.png");
	imageArray[imageNum++] = new imageItem(imageDir + "voip.png");
	imageArray[imageNum++] = new imageItem(imageDir + "ethernet.png");
	//next Generation
	imageArray[imageNum++] = new imageItem(imageDir +"PON.png");
	imageArray[imageNum++] = new imageItem(imageDir + "BPON.png");
	imageArray[imageNum++] = new imageItem(imageDir + "EPON.png");
	imageArray[imageNum++] = new imageItem(imageDir + "GPON.png");
	imageArray[imageNum++] = new imageItem(imageDir + "xiptv.png");
	imageArray[imageNum++] = new imageItem(imageDir + "ce.png");


			var totalImages = imageArray.length;
				function imageItem(image_location) {	 
	    			this.image_item = new Image();
	   			 this.image_item.src = image_location;
				}

				function get_ImageItemLocation(imageObj) {
	    			return(imageObj.image_item.src)
				}
	
				function randNum(x, y) {
				var range = y - x + 1;
				return Math.floor(Math.random() * range) + x;
				}

				function getNextImage() {
				if (random_display) {
					imageNum = randNum(0, totalImages-1);
				}else {
				imageNum = (imageNum+1) % totalImages;
				}

				var new_image = get_ImageItemLocation(imageArray[imageNum]);
				return(new_image);
				}
				function getPrevImage() {
				imageNum = (imageNum-1) % totalImages;
				var new_image = get_ImageItemLocation(imageArray[imageNum]);
				return(new_image);
				}

				function prevImage(place) {
				var new_image = getPrevImage();
				document[place].src = new_image;
				}

				function switchImage(place) {
				var new_image = getNextImage();
				document[place].src = new_image;
				var recur_call = "switchImage('"+place+"')";
				timerID = setTimeout(recur_call, interval);
				}

				function getImage() {
				imageNum = 0 % totalImages;
				var new_image = get_ImageItemLocation(imageArray[imageNum]);
				return(new_image);
				}

				function legacy(place){
				var new_image = getImage("images/homepage/tele_basics.png");
				document[place].src = new_image;
				}

				function getImage2() {
				imageNum = 4 % totalImages;
				var new_image = get_ImageItemLocation(imageArray[imageNum]);
				return(new_image);
				}

				function ip(place){
				var new_image = getImage2("images/homepage/ip_data.png");
				document[place].src = new_image;
				}

				function getImage3() {
				imageNum = 7 % totalImages;
				var new_image = get_ImageItemLocation(imageArray[imageNum]);
				return(new_image);
				}

				function generation(place){
				var new_image = getImage3("images/homepage/PON.png");
				document[place].src = new_image;
				}