// set the starting image.
var i = 0;			

// The time to wait before moving to the next image. Set to 3 seconds by default.
var wait = 4000;

// The Fade Function
function SwapImage(x,y) {
	var height = Element.getHeight(image_slide[x]);
	
	$('image-container').setStyle({
		'height':height+'px'
	}
    )
	new Effect.Fade($(image_slide[y]));
	new Effect.Appear($(image_slide[x]),  { queue: 'end' });
}

function GoNext() {
	
	var imageShow, imageHide;

	imageShow = i+1;
	imageHide = i;
	
	if (imageShow == NumOfImages) {
		SwapImage(0,imageHide);	
		i = 0;					
	} else {
		SwapImage(imageShow,imageHide);			
		i++;
	}
}

function GoPrevious() {

	var imageShow, imageHide;
				
	imageShow = i-1;
	imageHide = i;
	
	if (i == 0) {
		SwapImage(NumOfImages-1,imageHide);	
		i = NumOfImages-1;		
					
	} else {
		SwapImage(imageShow,imageHide);			
		i--;
	}
}

function initProgress()
{
	
	// the rest of this code inserts html at the top of the page that looks like this:
	//
	// <div id="overlay">
	//		<a href="#" onclick="hideProgress(); return false;"><img id="loadingImage" /></a>
	//	</div>

	var objBody = document.getElementsByTagName("body").item(0);
	
	// create overlay div and hardcode some functional styles (aesthetic styles are in CSS file)
	var objOverlay = document.createElement("div");
	objOverlay.setAttribute('id','overlay');
	//objOverlay.onclick = function () {hideProgress(); return false;}
	objOverlay.style.display = 'none';
	objOverlay.style.position = 'absolute';
	objOverlay.style.top = '0';
	objOverlay.style.left = '0';
	objOverlay.style.zIndex = '90';
 	objOverlay.style.width = '100%';
	objBody.insertBefore(objOverlay, objBody.firstChild);
	
	var arrayPageSize = getPageSize();
	var arrayPageScroll = getPageScroll();

	// preload and create loader image
	var imgPreloader = new Image();
	
	// if loader image found, create link to hide lightbox and create loadingimage
	imgPreloader.onload=function(){

		var objLoadingImageLink = document.createElement("a");
		objLoadingImageLink.setAttribute('href','#');
		//objLoadingImageLink.onclick = function () {return false;}
		objOverlay.appendChild(objLoadingImageLink);
		
		var objLoadingImage = document.createElement("img");
		objLoadingImage.src = loadingImage;
		objLoadingImage.setAttribute('id','loadingImage');
		objLoadingImage.style.position = 'absolute';
		objLoadingImage.style.display = 'none';
		objLoadingImage.style.zIndex = '150';
		objLoadingImageLink.appendChild(objLoadingImage);

		imgPreloader.onload=function(){};	//	clear onLoad, as IE will flip out w/animated gifs

		return false;
	}
	
	imgPreloader.src = loadingImage;	

}

function hideProgress()
{
	document.body.style.cursor = 'default';
	// get objects
	objOverlay = document.getElementById('overlay');

	// hide lightbox and overlay
	objOverlay.style.display = 'none';

	// make select boxes visible
	/*selects = document.getElementsByTagName("select");
    for (i = 0; i != selects.length; i++) {
		selects[i].style.visibility = "visible";
	}*/

	// disable keypress listener
	document.onkeypress = '';
}

var loadingImage = '../images/loading_big.gif';		


//
// getPageScroll()
// Returns array with x,y page scroll values.
// Core code from - quirksmode.org
//
function getPageScroll(){

	var yScroll;

	if (self.pageYOffset) {
		yScroll = self.pageYOffset;
	} else if (document.documentElement && document.documentElement.scrollTop){	 // Explorer 6 Strict
		yScroll = document.documentElement.scrollTop;
	} else if (document.body) {// all other Explorers
		yScroll = document.body.scrollTop;
	}

	arrayPageScroll = new Array('',yScroll) 
	return arrayPageScroll;
}



//
// getPageSize()
// Returns array with page width, height and window width, height
// Core code from - quirksmode.org
// Edit for Firefox by pHaez
//
function getPageSize(){
	
	var xScroll, yScroll;
	
	if (window.innerHeight && window.scrollMaxY) {	
		xScroll = document.body.scrollWidth;
		yScroll = window.innerHeight + window.scrollMaxY;
	} else if (document.body.scrollHeight > document.body.offsetHeight){ // all but Explorer Mac
		xScroll = document.body.scrollWidth;
		yScroll = document.body.scrollHeight;
	} else { // Explorer Mac...would also work in Explorer 6 Strict, Mozilla and Safari
		xScroll = document.body.offsetWidth;
		yScroll = document.body.offsetHeight;
	}
	
	var windowWidth, windowHeight;
	if (self.innerHeight) {	// all except Explorer
		windowWidth = self.innerWidth;
		windowHeight = self.innerHeight;
	} else if (document.documentElement && document.documentElement.clientHeight) { // Explorer 6 Strict Mode
		windowWidth = document.documentElement.clientWidth;
		windowHeight = document.documentElement.clientHeight;
	} else if (document.body) { // other Explorers
		windowWidth = document.body.clientWidth;
		windowHeight = document.body.clientHeight;
	}	
	
	// for small pages with total height less then height of the viewport
	if(yScroll < windowHeight){
		pageHeight = windowHeight;
	} else { 
		pageHeight = yScroll;
	}

	// for small pages with total width less then width of the viewport
	if(xScroll < windowWidth){	
		pageWidth = windowWidth;
	} else {
		pageWidth = xScroll;
	}


	arrayPageSize = new Array(pageWidth,pageHeight,windowWidth,windowHeight) 
	return arrayPageSize;
}


//
// pause(numberMillis)
// Pauses code execution for specified time. Uses busy code, not good.
// Code from http://www.faqts.com/knowledge_base/view.phtml/aid/1602
//
function pause(numberMillis) {
	var now = new Date();
	var exitTime = now.getTime() + numberMillis;
	while (true) {
		now = new Date();
		if (now.getTime() > exitTime)
			return;
	}
}

//
// getKey(key)
// Gets keycode. If 'x' is pressed then it hides the lightbox.
//

function getKey(e){
	if (e == null) { // ie
		keycode = event.keyCode;
	} else { // mozilla
		keycode = e.which;
	}
	key = String.fromCharCode(keycode).toLowerCase();
	
	if(key == 'x'){ hideProgress(); }
}


//
// listenKey()
//
function listenKey () {	document.onkeypress = getKey; }
	

//
// showLightbox()
// Preloads images. Pleaces new image in lightbox then centers and displays.
//
function showProgress(showImage)
{
	document.body.style.cursor = 'wait';
	// prep objects
	var objOverlay = document.getElementById('overlay');
	var objLightbox = document.getElementById('lightbox');
	var objLoadingImage = document.getElementById('loadingImage');
	
	var arrayPageSize = getPageSize();
	var arrayPageScroll = getPageScroll();

	// center loadingImage if it exists
	if (objLoadingImage && showImage) {
		
		objLoadingImage.style.top = (arrayPageScroll[1] + ((arrayPageSize[3] - 35 - objLoadingImage.height) / 2) + 'px');
		objLoadingImage.style.left = (((arrayPageSize[0] - 20 - objLoadingImage.width) / 2) + 'px');
		objLoadingImage.style.display = 'block';
	}

	// set height of Overlay to take up whole page and show
	objOverlay.style.height = (arrayPageSize[1] + 'px');
	objOverlay.style.display = 'block';

		// A small pause between the image loading and displaying is required with IE,
		// this prevents the previous image displaying for a short burst causing flicker.
		if (navigator.appVersion.indexOf("MSIE")!=-1){
			pause(250);
		} 

		// Hide select boxes as they will 'peek' through the image in IE
		/*selects = document.getElementsByTagName("select");
        for (i = 0; i != selects.length; i++) {
                selects[i].style.visibility = "hidden";
        }
*/
		// After image is loaded, update the overlay height as the new image might have
		// increased the overall page height.
		arrayPageSize = getPageSize();
		objOverlay.style.height = (arrayPageSize[1] + 'px');
		
		return false;
		
}