var interval = 3500; //length of pause between pictures
var random_display = 0; //0=sequential; 1=random
var imageDir = "images/"; //image path
var imageNum = 0;
imageArray = new Array();
imageArray[imageNum++] = new imageItem(imageDir + "slide01.jpg"); //1405
imageArray[imageNum++] = new imageItem(imageDir + "header.jpg");
imageArray[imageNum++] = new imageItem(imageDir + "slide02.jpg"); //1403
imageArray[imageNum++] = new imageItem(imageDir + "slide03.jpg"); //1416
imageArray[imageNum++] = new imageItem(imageDir + "slide04.jpg"); //1408
imageArray[imageNum++] = new imageItem(imageDir + "slide05.jpg"); //1414
imageArray[imageNum++] = new imageItem(imageDir + "slide06.jpg"); //1407
imageArray[imageNum++] = new imageItem(imageDir + "slide07.jpg"); //1412
imageArray[imageNum++] = new imageItem(imageDir + "slide08.jpg"); //1410
imageArray[imageNum++] = new imageItem(imageDir + "slide09.jpg"); //1410
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;
	document.getElementById('header').style.backgroundImage="url(" + new_image + ")";
	var recur_call = "switchImage('"+place+"')";
	timerID = setTimeout(recur_call, interval);
}