var overlay = null;
var overlayContainer = null;
var imageLocationPath = "";

var images = Array();

var currentIndex = null;

var overlayImage = null;

function keyPressHandler(e) {
      var kC  = (window.event) ?    // MSIE or Firefox?
                 event.keyCode : e.keyCode;
      var Esc = (window.event) ?   
                27 : e.DOM_VK_ESCAPE // MSIE : Firefox
      if(kC==Esc)
         hideImageOverlay()
   }

function initOverlay(loc, i)
{
	imageLocationPath = loc;
	overlay = document.getElementById('overlay');
	overlayContainer = document.getElementById('overlayContainer');
	 
	var overlayImageContainer = document.getElementById('overlayImageContainer');
	
	images = i;
	
	for(i = 0; i < images.length; i++) {
		if(images[i] != '') {
			overlayImageContainer.innerHTML += '<img id="' + images[i] + '" src="' + loc + '/' + images[i] + '" alt="image" style="display:none"/>';
		}
	}
}

function scrollOverlay()
{
	var offsetTop = 0;
	var offsetLeft = 0;
	if (self.pageYOffset) { // all except Explorer
		offsetLeft = self.pageXOffset;
		offsetTop = self.pageYOffset;
	} else if (document.documentElement && document.documentElement.scrollTop) { // Explorer 6 Strict
		offsetLeft = document.documentElement.scrollLeft;
		offsetTop = document.documentElement.scrollTop;
	} else if (document.body) { // all other Explorers
		offsetLeft = document.body.scrollLeft;
		offsetTop = document.body.scrollTop;
	}

	overlay.style.top = offsetTop + 'px';
	overlay.style.left = offsetLeft + 'px';
	overlayContainer.style.top = (offsetTop + 50) +'px';
	overlayContainer.style.left = offsetLeft + 'px';
}

function showImage(imageIndex)
{
	if(!overlay || !overlayContainer) {
		return true;
	}
	
	if(overlayImage) {
		overlayImage.style.display = 'none';
	}
	
	currentIndex = imageIndex;
	
	overlayImage = document.getElementById(images[imageIndex]);
	overlayImage.style.display = 'inline';
		
	scrollOverlay();
	overlay.style.display = 'block';
	overlayContainer.style.display = 'block';
		
	return false;
}

function nextImage()
{
	if(currentIndex + 1 > images.length - 1) {
		showImage(0);
	} else {
		showImage(currentIndex + 1);
	}
}

function previousImage()
{
	if(currentIndex - 1 < 0) {
		showImage(images.length - 1);
	} else {
		showImage(currentIndex - 1);
	}
}

function hideImageOverlay()
{
	overlay.style.display = 'none';
	overlayContainer.style.display = 'none';
	overlayImage.style.display = 'none';
}