// changes text of photo

var interval = 3000; 

function initial(index) {
	document.getElementById(index).innerHTML = "<b>Photo 1 of " + number_of_image + "</b>";
//	document.getElementById("startSlide").value="hello!";
}

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 getNextImage(index) {
	ImageNum = (ImageNum+1) % number_of_image;
	var new_image = get_ImageItemLocation(imageArray[ImageNum]);
	document.getElementById(index).innerHTML = "<b>Photo " + (ImageNum+1) + " of " + number_of_image + "</b>";
	return(new_image);
}

function getPrevImage(index) {
	if(ImageNum==0) { ImageNum=number_of_image-1; }
	else { ImageNum = (ImageNum-1) % number_of_image; }
	var new_image = get_ImageItemLocation(imageArray[ImageNum]);
	document.getElementById(index).innerHTML = "<b>Photo " + (ImageNum+1) + " of " + number_of_image + "</b>";
	return(new_image);
}

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

function nextImage(btn, place, index) {
	var new_image = getNextImage(index);
	resetTimer(btn, place, index);
	document[place].src = new_image;
}

function rotateImage(btn, place, index) {
	if(document.getElementById(btn).value=="Start Slideshow") {
		document.getElementById(btn).value="Stop Slideshow";
		var recur_call = "slideShow('"+place+"', '"+index+"')";
		timerID = setTimeout(recur_call, interval);
	} else {
		document.getElementById(btn).value="Start Slideshow";
		clearTimeout(timerID);
		timerID=0;
	}
}

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

function resetTimer(btn, place,index) {
   if(document.getElementById(btn).value=="Stop Slideshow") {
		clearTimeout(timerID);
		var recur_call = "slideShow('"+place+"', '"+index+"')";
		timerID = setTimeout(recur_call, interval);
   }
}