function getPageScroll(){

	var yScroll;

	if (self.pageYOffset) {
		yScroll = self.pageYOffset;
	} else if (document.documentElement && document.documentElement.scrollTop){	 // Explorer 6 Strict
		yScroll = document.documentElement.scrollTop;
	} else if (document.body) {// all other Explorers
		yScroll = document.body.scrollTop;
	}

	arrayPageScroll = new Array('',yScroll) 
	return arrayPageScroll;
}



//
// getPageSize()
// Returns array with page width, height and window width, height
// Core code from - quirksmode.org
// Edit for Firefox by pHaez
//
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){ // all but Explorer Mac
		xScroll = document.body.scrollWidth;
		yScroll = document.body.scrollHeight;
	} else { // Explorer Mac...would also work in Explorer 6 Strict, Mozilla and Safari
		xScroll = document.body.offsetWidth;
		yScroll = document.body.offsetHeight;
	}
	
	var windowWidth, windowHeight;
	if (self.innerHeight) {	// all except Explorer
		windowWidth = self.innerWidth;
		windowHeight = self.innerHeight;
	} else if (document.documentElement && document.documentElement.clientHeight) { // Explorer 6 Strict Mode
		windowWidth = document.documentElement.clientWidth;
		windowHeight = document.documentElement.clientHeight;
	} else if (document.body) { // other Explorers
		windowWidth = document.body.clientWidth;
		windowHeight = document.body.clientHeight;
	}	
	
	// for small pages with total height less then height of the viewport
	if(yScroll < windowHeight){
		pageHeight = windowHeight;
	} else { 
		pageHeight = yScroll;
	}

	// for small pages with total width less then width of the viewport
	if(xScroll < windowWidth){	
		pageWidth = windowWidth;
	} else {
		pageWidth = xScroll;
	}


	arrayPageSize = new Array(pageWidth,pageHeight,windowWidth,windowHeight) 
	return arrayPageSize;
}

function showLayer(width,height,address)
{
	var arrayPageSize = getPageSize();
	var arrayPageScroll = getPageScroll();
	
	var objStage = document.getElementById('stage');
	objStage.style.height=arrayPageSize[1]+50+'px';
	
	var objWrapper = document.getElementById('wrapper');
	objWrapper.setAttribute('src',address);
	var objStage = document.getElementById('stage');
	var objManagerWindow = document.getElementById('managerWindow');
	objStage.style.display = 'block';	
	
	


	objManagerWindow.style.width=width+'px';
	objManagerWindow.style.height=height+'px';
	objManagerWindow.style.top = (arrayPageScroll[1] + ((arrayPageSize[3] - 35 - height) / 2) + 'px');
	objManagerWindow.style.left = (((arrayPageSize[0] - 20 - width) / 2) + 'px');
	objManagerWindow.style.display = 'block';
	
}

function hideLayer(){
	var objWrapper = document.getElementById('wrapper');
	objWrapper.setAttribute('src',"blank.html");
	var objStage = document.getElementById('stage');
	objStage.style.display = 'none';	
	var objManagerWindow = document.getElementById('managerWindow');
	objManagerWindow.style.display = 'none';
}

function initLayer()
{
	var objBody = document.getElementsByTagName("body").item(0);
	var objStage = document.createElement("div");
	objStage.setAttribute('id','stage');
	objBody.insertBefore(objStage, objBody.firstChild);
	var objManagerWindow = document.createElement("div");
	objManagerWindow.setAttribute('id','managerWindow');
	objBody.insertBefore(objManagerWindow, objStage.nextSibling);
	var objWrapper = document.createElement("iframe");
	objWrapper.setAttribute('id','wrapper');
	objWrapper.setAttribute('frameBorder','0');
	objManagerWindow.appendChild(objWrapper);
	var objDesc = document.createElement("div");
	objDesc.setAttribute('id','desc');
	objManagerWindow.appendChild(objDesc);
	document.getElementById('desc').innerHTML = "<a href='#' onclick='hideLayer()'>Zamknij</a>";
}