var interval = 4000; 
var random_display = 0;
var image_dir = "./pictures/"
var ImageNum = 0;
var imageArray = new Array();
var number_of_image = 0;

function setup(i1, i2, i3, i4, i5, i6) {

    //var imageArray = new Array();
    this.imageArray[ImageNum++] = new imageItem(image_dir + i1);
    this.imageArray[ImageNum++] = new imageItem(image_dir + i2);
    this.imageArray[ImageNum++] = new imageItem(image_dir + i3);
    this.imageArray[ImageNum++] = new imageItem(image_dir + i4);
    this.imageArray[ImageNum++] = new imageItem(image_dir + i5);
    this.imageArray[ImageNum++] = new imageItem(image_dir + i6);
    
    this.number_of_image = imageArray.length+1;
}

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, number_of_image-1);
    }
    else {
        ImageNum = (ImageNum+1) % number_of_image;
        //alert(ImageNum);
    }
    if (ImageNum < 1) {
        ImageNum = 1;
    }
    var new_image = get_ImageItemLocation(imageArray[ImageNum-1]);
    return(new_image);
}

function getPrevImage() {
    ImageNum = (ImageNum-1) % number_of_image;
    var new_image = get_ImageItemLocation(imageArray[ImageNum]);
    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, interval);
}