function createRequestObject() {
    var req;

    if (window.XMLHttpRequest) {
        req = new XMLHttpRequest();
    }
    else if (window.ActiveXObject) {
        req = new ActiveXObject("Microsoft.XMLHTTP");
    }
    else {
        alert('XMLHttpRequest object not created');
    }

    return req;
}

function sendRequest(pc, veld1, veld2, veld3, veld4) {
    if (pc.length > 0) {
        v1 = veld1;
        v2 = veld2;
        v3 = veld3;
        v4 = veld4;
        
        http.open('get', '/Postcode.aspx?Postcode=' + pc);
        http.onreadystatechange = handleResponse;
        http.send(null);
    }
}

function handleResponse() {
    if (http.readyState == 4 && http.status == 200) {
        if (http.responseText) {
            _response = http.responseText.split("#");
            _naam = _response[0];
            _adres = _response[1];
            _postcode = _response[2] + " " + _response[3];            
            _telefoon = _response[4];

            v1.innerHTML = _naam;
            v2.innerHTML = _adres;
            v3.innerHTML = _postcode;
            v4.innerHTML = _telefoon;
        }
    }
}

var http = createRequestObject();
var v1 = null;
var v2 = null;
var v3 = null;
var v4 = null;