function createRequestObject() {
    var req;
    if(window.XMLHttpRequest){
        // Firefox, Safari, Opera...
        req = new XMLHttpRequest();
    } else if(window.ActiveXObject) {
        // Internet Explorer 5+
        req = new ActiveXObject("Microsoft.XMLHTTP");
    } else {
        // There is an error creating the object,
        // just as an old browser is being used.
        alert("There was a problem creating the XMLHttpRequest object");
    }
    return req;
}

// Make the XMLHttpRequest object
var http = createRequestObject();

// Normale functie
function sendRequest(url, output) {
    // Open PHP script for requests
    http.open("GET", url, true);
    http.onreadystatechange = function() {handleResponse(output);};
    http.send(null);
}   

function handleResponse(div) {
    if(http.readyState == 4 && http.status == 200){
        // Text returned FROM PHP script
        var response = http.responseText;
        if(response) {
            document.getElementById(div).innerHTML = response; 
        }
    }
}