var interval = 5000; 
var random_display = 0;
var image_dir = ""
var ImageNum = 0;

function imageItem(image_location) {
this.image_item = new Image();
this.image_item.src = image_location;
}

function get_ImageItemLocation(imageObj) {
return(imageObj[0].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, number_of_image-1);
}
else {
ImageNum = (ImageNum+1) % number_of_image;
}
var new_image = get_ImageItemLocation(imageArray[ImageNum]);
var new_x = imageArray[ImageNum][1];
var new_y = imageArray[ImageNum][2];
var new_header = imageArray[ImageNum][3];
return new Array(new_image, new_x, new_y, new_header);
}

function getPrevImage() {
ImageNum = (ImageNum-1 > -1)? ImageNum-1 : number_of_image-1;
var new_image = get_ImageItemLocation(imageArray[ImageNum]);
var new_x = imageArray[ImageNum][1];
var new_y = imageArray[ImageNum][2];
var new_header = imageArray[ImageNum][3];
return new Array(new_image, new_x, new_y, new_header);
}

function prevImage(place) {
var new_set = getPrevImage();
document[place].src = new_set[0];
document[place].width = new_set[1];
document[place].height = new_set[2];
document.getElementById('atitle').innerHTML = new_set[3];
}

function rotateImage(place) {
var new_set = getNextImage();
document[place].src = new_set[0];
document[place].width = new_set[1];
document[place].height = new_set[2];
document.getElementById('atitle').innerHTML = new_set[3];
var recur_call = "rotateImage('"+place+"')";
timerID = setTimeout(recur_call, interval);
}

function startTimer(place) {
	var recur_call = "rotateImage('"+place+"')";
  timerID = setTimeout(recur_call, interval);
}