https://www.bestbassgear.com/js/magestore/bannerslider/lightbox.js?q=051216

1/**
2* Lightbox
3*
4* This libary is used to create a lightbox in a web application. This library
5* requires the Prototype 1.6 library and Script.aculo.us core, effects, and dragdrop
6* libraries. To use, add a div containing the content to be displayed anywhere on
7* the page. To create the lightbox, add the following code:
8*
9* var test;
10*
11* Event.observe(window, 'load', function () {
12* test = new Lightbox('idOfMyDiv');
13* });
14*
15* Event.observe('lightboxLink', 'click', function () {
16* test.open();
17* });
18*
19* Event.observe('closeLink', 'click', function () {
20* test.close();
21* });
22*
23*/
24var Lightbox = Class.create({
25	open : function () {
26		this._centerWindow(this.container);
27		this._fade('open', this.container);
28	},
29	close : function () {
30		this._fade('close', this.container);
31	},
32	_fade : function fadeBg(userAction,whichDiv){
33		if(userAction=='close'){
34			new Effect.Opacity('bg_fade',
35			{duration:.2,
36			from:0.6,
37			to:0,
38			afterFinish:this._makeInvisible,
39			afterUpdate:this._hideLayer(whichDiv)});
40			}else{
41			new Effect.Opacity('bg_fade',
42			{duration:.2,
43			from:0,
44			to:0.6,
45			beforeUpdate:this._makeVisible,
46			afterFinish:this._showLayer(whichDiv)});
47		}
48	},
49	_makeVisible : function makeVisible(){
50		$("bg_fade").style.visibility="visible";
51	},
52	_makeInvisible : function makeInvisible(){
53		$("bg_fade").style.visibility="hidden";
54	},
55	_showLayer : function showLayer(userAction){
56		$(userAction).style.display="block";
57	},
58	_hideLayer : function hideLayer(userAction){
59		$(userAction).style.display="none";
60	},
61	_centerWindow : function centerWindow(element) {
62		var windowHeight = parseFloat($(element).getHeight())/2;
63		var windowWidth = parseFloat($(element).getWidth())/2;
64		if(typeof window.innerHeight != 'undefined') {
65			$(element).style.top = Math.round(document.body.offsetTop + ((window.innerHeight - $(element).getHeight()))/2)+'px';
66			$(element).style.left = Math.round(document.body.offsetLeft + ((window.innerWidth - $(element).getWidth()))/2)+'px';
67			} else {
68			$(element).style.top = Math.round(document.body.offsetTop + ((document.documentElement.offsetHeight - $(element).getHeight()))/2)+'px';
69			$(element).style.left = Math.round(document.body.offsetLeft + ((document.documentElement.offsetWidth - $(element).getWidth()))/2)+'px';
70		}
71	},
72	initialize : function(containerDiv) {
73		this.container = containerDiv;
74		if($('bg_fade') == null) {
75		var screen = new Element('div', {'id': 'bg_fade'});
76		document.body.appendChild(screen);
77		}
78		this._hideLayer(this.container);
79	}
80});