function httpObject()
  {
    var object;
    var browser = navigator.appName;
    if(browser == "Microsoft Internet Explorer") { object = new ActiveXObject("Microsoft.XMLHTTP"); }
      else { object = new XMLHttpRequest(); }
    return object;
  }

var http = httpObject();

function ajaxload(args)
  {
    document.getElementById('headlines').innerHTML = "<img src='/incl/loading.gif'>&nbsp;&nbsp;Daten werden geladen...";
    http.open('get', '/incl/newslist.php?'+args);
    http.onreadystatechange = handleResponse;
    http.send(null);
  }

function setfeed(feedid)
  {
    var checked=document.getElementById(feedid).checked;
    if(checked==true) { ajaxload('addfeed='+feedid); }
    else { ajaxload('delfeed='+feedid); }
  }

function handleResponse() {
    if(http.readyState == 4){
        var response = http.responseText;
        document.getElementById('headlines').innerHTML = response;
    }
}

//var minutes = 0.1; = 6 sec
var minutes = 3; // 15 mins
setInterval("ajaxload('')", minutes*60000);