function getXMLHttpRequest() { 
	if (window.XMLHttpRequest) {
		http_request=new XMLHttpRequest()
	} else if (window.ActiveXObject){
		try {
			http_request = new ActiveXObject("Msxml2.XMLHTTP");
		} catch (e) {
			try {
				http_request = new ActiveXObject("Microsoft.XMLHTTP");
			} catch (e) {
				alert('fout bij laden http_request');	
			}
		}
	}

	return http_request;

} 



function getXMLHttpRequest2() {
	http_request = false;
	
	if (window.XMLHttpRequest) { // Mozilla, Safari,...
		http_request = new XMLHttpRequest();
		if (http_request.overrideMimeType) {
			http_request.overrideMimeType('text/xml');
		}
	} else if (window.ActiveXObject) { // IE
		try {
		http_request = new ActiveXObject("Msxml2.XMLHTTP");
		} catch (e) {
			try {
				http_request = new ActiveXObject("Microsoft.XMLHTTP");
			} catch (e) {}
		}
	}

	if (!http_request) {
		alert('Giving up :( Cannot create an XMLHTTP instance');
	}          
	return http_request;
}

function XMLPostRequest(url, data, callback) {
	http_request = getXMLHttpRequest();
	http_request.onreadystatechange = callback;
	http_request.open('POST', url, true);
	http_request.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
	http_request.send(data);
	return http_request;
}

function XMLGetRequest(url, data, callback) {
	
	http_request = getXMLHttpRequest();
	http_request.onreadystatechange = callback;
	http_request.open('GET', url, true);
	http_request.send(data);
	return http_request;
}


function printXML(xmldoc) {
	if (window.ActiveXObject) { 
		return xmldoc.xml
	} else { 
		var serializer_object = new XMLSerializer();
		return serializer_object.serializeToString(xmldoc);		
	}

	
}