function getPageSize(){
	
	var xScroll, yScroll;
	var pageHeight = 0;
	var pageWidth = 0;
	
	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;
	}


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

function load(url, containerid){
	var page_request = false
	if (window.XMLHttpRequest) // if Mozilla, Safari etc
		page_request = new XMLHttpRequest()
	else if (window.ActiveXObject){ // if IE
		try {
			page_request = new ActiveXObject("Msxml2.XMLHTTP")
		} 
		catch (e){
			try{
				page_request = new ActiveXObject("Microsoft.XMLHTTP")
			}
			catch (e){}
		}
	}
	if (url.match("[?]")) {
		var split = new Array();
		split = url.split("?");
		url = split[0];
		var parameters = split[1];
	} else {
		var parameters = '';
	}
	page_request.onreadystatechange=function(){
		loadpage(page_request, containerid)
	}
	page_request.open('POST', url, true);
	page_request.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
	page_request.setRequestHeader("Content-length", parameters.lenght);
	page_request.setRequestHeader("Connection", "close");
	page_request.send(parameters);
}

function loadpage(page_request, containerid){
	if (page_request.readyState == 4 && (page_request.status==200 || window.location.href.indexOf("http")==-1)) {
		document.getElementById(containerid).innerHTML=page_request.responseText;
		document.getElementById('loading').style.visibility = 'hidden';
	}
}

function openTextForm(page) {
	Lightbox.prototype.initialize();
	var arrayPageSize = getPageSize();
	Element.setHeight('overlay2', arrayPageSize[1]);
	new Effect.Appear('overlay2', { duration: 0.2, from: 0.0, to: 0.8 });
	document.getElementById('textform').style.display = 'block';
	document.getElementById('textform').style.left = ((arrayPageSize[2] / 2) - 300) + "px";
	
	var titel = '';
	var text = '';
	document.getElementById('loader').style.display = 'block';
	
	sendAjaxRequest('includes/getitem.php?item=' + page, function(ajaxRequest) {
		var ans = eval('(' + ajaxRequest.responseText + ')');
		if (ans.succes) {
			titel = ans.titel;
			text = ans.text;
		
			document.getElementById('containertitle').innerHTML = titel;
			document.getElementById('textload').innerHTML = text;
			document.getElementById('loader').style.display = 'none';
		} else {
			//fout!
			alert('Er was een fout met het verwerken van de request.');
		}
	});
	
}

function sendAjaxRequest(url, eventhandler) {
  if (window.ActiveXObject) {
	var xhr = new ActiveXObject("Microsoft.XMLHTTP")
  } else if (window.XMLHttpRequest) {
	var xhr = new XMLHttpRequest();
  }
  
  if (url.match("[?]")) {
		var split = new Array();
		split = url.split("?");
		url = split[0];
		var postdata  = split[1];
	} else {
		var postdata = '';
	}
  
  xhr.onreadystatechange = function() {
	 if(xhr.readyState == 4)
		if(xhr.status == 200) {
		   eventhandler(xhr);
		} else {
		   document.body.innerHTML = xhr.responseText
		}
  }
  xhr.open("POST", url, true )
  xhr.setRequestHeader('Content-Type','application/x-www-form-urlencoded')
  xhr.send(postdata)
}

function loadCarousel(page) {
	document.getElementById("carousel-overlay").style.display = "block";
	sendAjaxRequest('includes/carousel.php?page=' + page, function(ajaxRequest) {
		var ans = eval('(' + ajaxRequest.responseText + ')');
		if (ans.succes) {
			document.getElementById('carousel').innerHTML = ans.html;
			document.getElementById("carousel-overlay").style.display = "none";
			Lightbox.prototype.initialize();
		} else {
			//fout!
			alert('Er was een fout met het verwerken van de request.');
		}
	});
}

function openNieuws() {
	sendAjaxRequest('includes/getnieuws.php', function(ajaxRequest) {
		var ans = eval('(' + ajaxRequest.responseText + ')');
		if (ans.succes) {
			document.getElementById('leftNews').innerHTML = ans.left;
			if (ans.right) {
				document.getElementById('rightNews').innerHTML = ans.right;
			}
			document.getElementById('nieuwsform').style.display = "block";
		} else {
			//fout!
			alert('Er was een fout met het verwerken van de request.');
		}
	});
}

function closeNieuws() {
	document.getElementById('nieuwsform').style.display = "none";
}

function closeTextForm() {
	document.getElementById('textload').innerHTML = "";
	document.getElementById('textform').style.display = "none";
	new Effect.Fade('overlay2', { duration: 0.2});
	document.getElementById('overlay2').style.display = "none";
}