var interval = 5; // delay between rotating images (in seconds)
var random_display = 0; // 0 = no, 1 = yes
interval *= 1000;

var image_index = 0;

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 generate(x, y) {
	var range = y - x + 1;
	return Math.floor(Math.random() * range) + x;
}
function getNextImage() {
	if (random_display) {
		image_index = generate(0, number_of_image-1);
	}
	else {
		image_index = (image_index+1) % number_of_image;
	}
	var new_image = get_ImageItemLocation(image_list[image_index]);
	return(new_image);
}
function rotateImage(place) {
	var new_image = getNextImage();
	document[place].src = new_image;
	var recur_call = "rotateImage('"+place+"')";
	setTimeout(recur_call, interval);
}