var loadingImage = 'images/loading.gif';	

function getPageScroll(){
var yScroll;
if (self.pageYOffset) {
yScroll = self.pageYOffset;
} else if (document.documentElement && document.documentElement.scrollTop){
yScroll = document.documentElement.scrollTop;
} else if (document.body) {
yScroll = document.body.scrollTop;
}
arrayPageScroll = new Array('',yScroll) 
return arrayPageScroll;
}

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){
xScroll = document.body.scrollWidth;
yScroll = document.body.scrollHeight;
} else {
xScroll = document.body.offsetWidth;
yScroll = document.body.offsetHeight;
}
var windowWidth, windowHeight;
if (self.innerHeight) {
windowWidth = self.innerWidth;
windowHeight = self.innerHeight;
} else if (document.documentElement && document.documentElement.clientHeight) {
windowWidth = document.documentElement.clientWidth;
windowHeight = document.documentElement.clientHeight;
} else if (document.body) {
windowWidth = document.body.clientWidth;
windowHeight = document.body.clientHeight;
}	
if(yScroll < windowHeight){
pageHeight = windowHeight;
} else { 
pageHeight = yScroll;
}
if(xScroll < windowWidth){	
pageWidth = windowWidth;
} else {
pageWidth = xScroll;
}
arrayPageSize = new Array(pageWidth,pageHeight,windowWidth,windowHeight) 
return arrayPageSize;
}


function pause(numberMillis) {
var now = new Date();
var exitTime = now.getTime() + numberMillis;
while (true) {
now = new Date();
if (now.getTime() > exitTime)
return;
}
}

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

function listenKey () {	document.onkeypress = getKey; }
	
function showLightbox(objLink){
var objOverlay = document.getElementById('overlay');
var objLightbox = document.getElementById('lightbox');
var objCaption = document.getElementById('lightboxCaption');
var objImage = document.getElementById('lightboxImage');
var objLoadingImage = document.getElementById('loadingImage');
var objLightboxDetails = document.getElementById('lightboxDetails');
var arrayPageSize = getPageSize();
var arrayPageScroll = getPageScroll();
if (objLoadingImage) {
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';
}
objOverlay.style.height = (arrayPageSize[1] + 'px');
objOverlay.style.display = 'block';
imgPreload = new Image();
imgPreload.onload=function(){
objImage.src = objLink.href;
var lightboxTop = arrayPageScroll[1] + ((arrayPageSize[3] - 35 - imgPreload.height) / 2);
var lightboxLeft = ((arrayPageSize[0] - 20 - imgPreload.width) / 2);
objLightbox.style.top = (lightboxTop < 0) ? "0px" : lightboxTop + "px";
objLightbox.style.left = (lightboxLeft < 0) ? "0px" : lightboxLeft + "px";
objLightboxDetails.style.width = imgPreload.width + 'px';
if(objLink.getAttribute('title')){
objCaption.style.display = 'block';
objCaption.innerHTML = objLink.getAttribute('title');
} else {
objCaption.style.display = 'none';
}
if (navigator.appVersion.indexOf("MSIE")!=-1){
pause(250);
} 
if (objLoadingImage) {	objLoadingImage.style.display = 'none'; }
selects = document.getElementsByTagName("select");
for (i = 0; i != selects.length; i++) {
selects[i].style.visibility = "hidden";
}
objLightbox.style.display = 'block';
arrayPageSize = getPageSize();
objOverlay.style.height = (arrayPageSize[1] + 'px');
listenKey();
return false;
}
imgPreload.src = objLink.href;
}

function hideLightbox(){
objOverlay = document.getElementById('overlay');
objLightbox = document.getElementById('lightbox');
objOverlay.style.display = 'none';
objLightbox.style.display = 'none';
selects = document.getElementsByTagName("select");
for (i = 0; i != selects.length; i++) {
selects[i].style.visibility = "visible";
}
document.onkeypress = '';
}

function initLightbox(){
if (!document.getElementsByTagName){ return; }
var anchors = document.getElementsByTagName("a");
for (var i=0; i<anchors.length; i++){
var anchor = anchors[i];
if (anchor.getAttribute("href") && (anchor.getAttribute("rel") == "lightbox")){
anchor.onclick = function () {showLightbox(this); return false;}
}
}
var objBody = document.getElementsByTagName("body").item(0);
var objOverlay = document.createElement("div");
objOverlay.setAttribute('id','overlay');
objOverlay.onclick = function () {hideLightbox(); 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();
var imgPreloader = new Image();
imgPreloader.onload=function(){
var objLoadingImageLink = document.createElement("a");
objLoadingImageLink.setAttribute('href','#');
objLoadingImageLink.onclick = function () {hideLightbox(); return false;}
objOverlay.appendChild(objLoadingImageLink);
var objLoadingImage = document.createElement("img");
objLoadingImage.src = loadingImage;
objLoadingImage.setAttribute('id','loadingImage');
objLoadingImage.style.position = 'absolute';
objLoadingImage.style.zIndex = '150';
objLoadingImageLink.appendChild(objLoadingImage);
imgPreloader.onload=function(){};
return false;
}
imgPreloader.src = loadingImage;

// create lightbox div
var objLightbox = document.createElement("div");
objLightbox.setAttribute('id','lightbox');
objLightbox.style.display = 'none';
objLightbox.style.position = 'absolute';
objLightbox.style.zIndex = '100';	
objBody.insertBefore(objLightbox, objOverlay.nextSibling);

// create link
var objLink = document.createElement("a");
objLink.setAttribute('href','#');
objLink.setAttribute('title','Klicken, um Foto zu schliessen');
objLink.onclick = function () {hideLightbox(); return false;}
objLightbox.appendChild(objLink);

// create image
var objImage = document.createElement("img");
objImage.setAttribute('id','lightboxImage');
objLink.appendChild(objImage);

// create details div, a container for the caption
var objLightboxDetails = document.createElement("div");
objLightboxDetails.setAttribute('id','lightboxDetails');
objLightbox.appendChild(objLightboxDetails);

// create caption
var objCaption = document.createElement("div");
objCaption.setAttribute('id','lightboxCaption');
objCaption.style.display = 'none';
objLightboxDetails.appendChild(objCaption);

}

function addLoadEvent(func){
var oldonload = window.onload;
if (typeof window.onload != 'function'){
window.onload = func;
} else {
window.onload = function(){
oldonload();
func();
}
}
}

addLoadEvent(initLightbox);