var IE = !!(window.attachEvent && !window.opera);
var Class = {
  create: function() {
    return function() {
      this.initialize.apply(this, arguments);
    }
  }
}

var lightbox = Class.create();
lightbox.prototype = {

	yPos : 0,
	xPos : 0,

	initialize: function(rel) {
		if(!rel) { this.content = ctrl.rel; } else { this.content = rel; }
	},

	activate: function(){
		if (IE){
			this.getScroll();
			this.prepareIE('100%', 'hidden');
			this.setScroll(0,0);
			this.hideSelects('hidden');
		};
		this.displayLightbox("block");
	},

	prepareIE: function(height, overflow){
		bod = document.getElementsByTagName('body')[0];
		bod.style.height = height;
		bod.style.overflow = overflow;

		htm = document.getElementsByTagName('html')[0];
		htm.style.height = height;
		htm.style.overflow = overflow;
	},

	hideSelects: function(visibility){
		selects = document.getElementsByTagName('select');
		for(i = 0; i < selects.length; i++) {
			selects[i].style.visibility = visibility;
		}
	},

	getScroll: function(){
		if (self.pageYOffset) {
			this.yPos = self.pageYOffset;
		} else if (document.documentElement && document.documentElement.scrollTop){
			this.yPos = document.documentElement.scrollTop;
		} else if (document.body) {
			this.yPos = document.body.scrollTop;
		}
	},

	setScroll: function(x, y){
		window.scrollTo(x, y);
	},

	displayLightbox: function(display){
		if (document.getElementById('overlay') != null)
			document.getElementById('overlay').style.display = display;
		document.getElementById(this.content).style.display = display;
	},

	deactivate: function(){
		if (IE){
			this.setScroll(0,this.yPos);
			this.prepareIE("auto", "auto");
			this.hideSelects("visible");
		}
		this.displayLightbox("none");
	}
};

function addLightboxMarkup() {
	bod 				= document.getElementsByTagName('body')[0];
	overlay 			= document.createElement('div');
	overlay.id			= 'overlay';
	bod.appendChild(overlay);
}

function addOnload (func) {
	var oldOnload = function () {};
	if (typeof window.onload == 'function') {
		oldOnload = window.onload;
	}
	window.onload = function () {
		oldOnload();
		eval(func+'();');
	}
}
addOnload('addLightboxMarkup');