// stores the reference to the XMLHttpRequest object
var xmlHttp = createXmlHttpRequestObject();


// retrieves the XMLHttpRequest object
function createXmlHttpRequestObject(){
	// will store the reference to the XMLHttpRequest object
	var xmlHttp;
	try{
		xmlHttp = new XMLHttpRequest();	
	}catch(e){
		var XmlHttpVersions = new Array('MSXML2.XMLHTTP.6.0',
										'MSXML2.XMLHTTP.5.0',
										'MSXML2.XMLHTTP.4.0',
										'MSXML2.XMLHTTP.3.0',
										'MSXML2.XMLHTTP',
										'Microsoft.XMLHTTP');
		for(var i=0;i<XmlHttpVersions.length && !xmlHttp; i++){
			try{
				xmlHttp = new ActiveXObject(XmlHttpVersions[i]);
			}catch(e){}
		}
	}
	// return the created object or display an error message
	if (!xmlHttp)
		document.getElementById("nieuws").innerHTML ="<span id='klein'>Error creating the XMLHttpRequest object.</span>";
	else
		return xmlHttp;
}

// make asynchronous HTTP request using the XMLHttpRequest object
function process(){
	if(xmlHttp){
		try{
			xmlHttp.open("GET", "nieuws_ajax.php", true);
			xmlHttp.onreadystatechange = handleRequestStateChange; //handleServerResponse;
			xmlHttp.send(null);	
		}catch(e){
			//alert("Can't connect to server:\n"+ e.toString());
			setTimeout('process()', 5000);
		}	
	}
}

function handleRequestStateChange(){
	if(xmlHttp.readyState ==4){
		if(xmlHttp.status == 200){
			try{
				handleServerResponse();	
			}catch(e){
				document.getElementById("nieuws").innerHTML ="<span id='klein'>Error reading response:<br/>"+ e.toString()+"</span>";
			}	
		}else{
			document.getElementById("nieuws").innerHTML = "<span id='klein'>Problem with receiving data for nieuws!!"+ xmlHttp.statusText+"</span>";
		}	
	}	
}

function handleServerResponse(){
		var xmlResponse = xmlHttp.responseXML;
		if(!xmlResponse || !xmlResponse.documentElement)
			throw("invalid XML Structure:\n" + xmlHttp.responseText);
		var rootNodeName = xmlResponse.documentElement.nodeName;
		if(rootNodeName =="parsererror")
			throw("invalid xml structure:\n" + xmlHttp.responseText);
		xmlRoot = xmlResponse.documentElement;

		title = xmlRoot.getElementsByTagName("titel");
		datum = xmlRoot.getElementsByTagName("datum");
		tekst = xmlRoot.getElementsByTagName("tekst");
		afbeelding = xmlRoot.getElementsByTagName("afbeelding");
		agendaitem = xmlRoot.getElementsByTagName("agendaitem");
		
		document.getElementById("nieuws").innerHTML = "<div id='titel'>"+title.item(0).firstChild.data+"<span class='datum'>"+datum.item(0).firstChild.data+"</span></div>";
		if(afbeelding.item(0).firstChild.data !=""){
			document.getElementById("nieuws").innerHTML +=   "<div id='image'><img src='"+afbeelding.item(0).firstChild.data+"' class='image'/></div>";
		}
		document.getElementById("nieuws").innerHTML += "<span id='klein'>"+tekst.item(0).firstChild.data+"</span><br />";
		document.getElementById("nieuws").innerHTML += "<a href='"+agendaitem.item(0).firstChild.data+"' class='newsitemlink'>lees meer...</a>";

		setTimeout('process()', 10000);
}