function layer(url,width,height)
{
	document.getElementById('layer').innerHTML='';
	ajaxRequest(url,'layer',0,'',showlayer(width,height));
}

function hidelayer()
{ 
	document.getElementById('layer').style.display='none';
	document.getElementById('layer').style.visibility='hidden';
	
	document.getElementById('overlay').style.display='none';
	document.getElementById('overlay').style.visibility='hidden';
}

function showlayer(width,height)
{
	tmparray = getPageSize();
	pageWidth = tmparray[0];
	pageHeight = tmparray[1];
	windowWidth = tmparray[2];
	windowHeight = tmparray[3];
	xScrolled = tmparray[4];
	yScrolled = tmparray[5];
	
	document.getElementById('layer').style.width=width+'px';
	document.getElementById('layer').style.height=height+'px';
	document.getElementById('layer').style.marginLeft='-'+(width/2)+'px';		
	
	//layer einblenden
	document.getElementById('layer').style.display='block';
	document.getElementById('layer').style.visibility='visible';
	
	//overlay einblenden
	document.getElementById('overlay').style.display='block';
	document.getElementById('overlay').style.visibility='visible';	
} 

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;
	}

	var xScrolled, yScrolled;
	if (self.pageYOffset) {
		xScrolled = self.pageXOffset;
		yScrolled = self.pageYOffset;
	} else if (document.documentElement && document.documentElement.scrollTop) {
		xScrolled = document.documentElement.scrollLeft;
		yScrolled = document.documentElement.scrollTop;
	} else if (document.body) {
		xScrolled = document.body.scrollLeft;
		yScrolled = document.body.scrollTop;
	}

	// 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, xScrolled, yScrolled);
	return arrayPageSize;
}