var interval = 2000;
var random_display = 0;
var imageDir = "images/";

/*
var imageNum = 0;

imageArray[imageNum] = new imageItem(imageDir + "SpicesSS001.png");
imageArray[imageNum++] = new imageItem(imageDir + "SpicesSS002.png");
imageArray[imageNum++] = new imageItem(imageDir + "SpicesSS003.png");
imageArray[imageNum++] = new imageItem(imageDir + "SpicesSS004.png");
imageArray[imageNum++] = new imageItem(imageDir + "SpicesSS005.png");
*/
var imageNum = 4;

imageArray = new Array( new imageItem(imageDir + "SpicesSS001.png"), 
						new imageItem(imageDir + "SpicesSS002.png"), 
						new imageItem(imageDir + "SpicesSS003.png"), 
						new imageItem(imageDir + "SpicesSS004.png"), 
						new imageItem(imageDir + "SpicesSS005.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() {
	if ((imageNum-1) < 0) {
		imageNum = totalImages-1;
	}	
	else {
		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);
}