var req;

function loadFile(url) {
      req = false;
document.getElementById('venster').innerHTML = "<B>Pagina bezig met laden...</B>";

if(window.XMLHttpRequest) {
      try {
                  req = new XMLHttpRequest();
} catch(e) {
                  req = false;
}

} else if(window.ActiveXObject) {
      try {
      req = new ActiveXObject("Msxml2.XMLHTTP");
      } catch(e) {
      try {
            req = new ActiveXObject("Microsoft.XMLHTTP");
      } catch(e) {
            req = false;
      }
            }
}
      if(req) {
            req.onreadystatechange = processReqChange;
            req.open("GET", url, true);
            req.send(null);
      }
}

function processReqChange() {

if (req.readyState == 4) {

if (req.status == 200) {

document.getElementById('venster').innerHTML = req.responseText;

} else {
alert("Probleem met verkrijgen van data:\n" +
req.statusText);
}
}
}