var loadingImage='i/loading.gif';
var closeButton='i/close.gif';

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

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

function showLightbox(objLink)
{
	// prep objects
	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();

	// center loadingImage if it exists
	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';
	}

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

	// preload image
	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';
		objCaption.style.display='block';

		var res='<span style="font-size:11px;">'+objLink.title+'</span>';
		objCaption.innerHTML=res;

		if (navigator.appVersion.indexOf("MSIE")!=-1){
			pause(150);
		}

		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');
		
		// Check for 'x' keypress
		listenKey();

		return false;
	}

	imgPreload.src=objLink.href;
	
}

// hideLightbox()
function hideLightbox()
{
	// get objects
	objOverlay=document.getElementById('overlay');
	objLightbox=document.getElementById('lightbox');

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

function initLightbox()
{
	if (!document.getElementsByTagName){ return; }
	var anchors=document.getElementsByTagName("a");

	// loop through all anchor tags
	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);
	
	// 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 () {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();

	// 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 () {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(){};//clear onLoad, as IE will flip out w/animated gifs

		return false;
	}

	imgPreloader.src=loadingImage;

	// create lightbox div, same note about styles as above
	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','Click to close');
	objLink.onclick=function () {hideLightbox(); return false;}
	objLightbox.appendChild(objLink);

	// preload and create close button image
	var imgPreloadCloseButton=new Image();

	// if close button image found, 
	imgPreloadCloseButton.onload=function(){

		var objCloseButton=document.createElement("img");
		objCloseButton.src=closeButton;
		objCloseButton.setAttribute('id','closeButton');
		objCloseButton.style.position='absolute';
		objCloseButton.style.zIndex='200';
		objLink.appendChild(objCloseButton);
		return false;
	}

	imgPreloadCloseButton.src=closeButton;

	// create image
	var objImage=document.createElement("img");
	objImage.setAttribute('id','lightboxImage');
	objLink.appendChild(objImage);
	
	// create details div, a container for the caption and keyboard message
	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);

	// create keyboard message
	var objKeyboardMsg=document.createElement("div");
	objKeyboardMsg.setAttribute('id','keyboardMsg');
	objKeyboardMsg.innerHTML=''/*'<a href="#" onclick="hideLightbox(); return false;">закрыть</a>'*/;
	objLightboxDetails.appendChild(objKeyboardMsg);
}