function makeHttpRequest(url)
{
    var 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('We are sorry but your browser doesn\'t support the feature used by the advertisements on this page.  Please contact the webmaster for more information.');
       return false;
   }
   
   http_request.onreadystatechange = function() {
       initAd(http_request);
   }
   
   http_request.open('GET', url, true);
   http_request.send(null);
}

function initAd(http_request) {
    var ep = 0;
    
    try {
        if (http_request.readyState == 4) {
                if (http_request.status == 200) {
                    ep = 1;
                    var xmldoc = http_request.responseXML;
                    ep = 2;
                    var content_node = xmldoc.getElementsByTagName('content').item(0).firstChild.nodeValue;
                    ep = 3;
                    var reload_node = xmldoc.getElementsByTagName('reload').item(0).firstChild.nodeValue;
                    ep = 4;
                    
                    document.getElementById('ajax-banner').innerHTML = content_node;           
                    
                    try {
                       clearTimeout(to);
                    } catch (e) {}

                    to = setTimeout("nextAd()", parseInt(reload_node));
                    
                } else {
                    alert('There was a problem with the request.');
                }
        }
    }
    catch( e ) {
        alert('Exception Thrown: ' + e.description + ' EC:' + ep);
    }
}

function nextAd()
{
    var now = new Date();
    var url = 'ad.aspx?ts=' + now.getTime();
    makeHttpRequest(url);
}