var delay = 2500; 
var random = 0;
var image_index =""
var i = 0;

imageArray = new Array();
imageArray[i++] = new imageItem(image_index + "images/slide01.jpg");
imageArray[i++] = new imageItem(image_index + "images/slide02.jpg");
imageArray[i++] = new imageItem(image_index + "images/slide03.jpg");
imageArray[i++] = new imageItem(image_index + "images/slide04.jpg");
imageArray[i++] = new imageItem(image_index + "images/slide05.jpg");
imageArray[i++] = new imageItem(image_index + "images/slide06.jpg");
imageArray[i++] = new imageItem(image_index + "images/slide07.jpg");
imageArray[i++] = new imageItem(image_index + "images/slide08.jpg");
imageArray[i++] = new imageItem(image_index + "images/slide09.jpg");
imageArray[i++] = new imageItem(image_index + "images/slide10.jpg");
imageArray[i++] = new imageItem(image_index + "images/slide11.jpg");
imageArray[i++] = new imageItem(image_index + "images/slide12.jpg");

var number_of_image = 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) {
i = randNum(0, number_of_image-1);
}
else {
i = (i+1) % number_of_image;
}
var new_image = get_ImageItemLocation(imageArray[i]);
return(new_image);
}


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

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

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