function fetch(url,target) {
        document.getElementById(target).innerHTML = "<div style='padding-top:20px;'><img src='images/spinner.gif' alt='loading' /> &nbsp; loading data...</div>";
        if (window.XMLHttpRequest) {
                req = new XMLHttpRequest();
                req.onreadystatechange = function() {fetchDone(target);};
                req.open("GET", url, true);
                req.send(null);
        } else if (window.ActiveXObject) {
                req = new ActiveXObject("Microsoft.XMLHTTP");
                if(req) {
                        req.onreadystatechange = function() {fetchDone(target+"&f=html");};
                        req.open("GET", url, true);
                        req.send();
                }
        }
}
function fetchDone(target) {
        if(req.readyState == 4) {
                if(req.status == 200 || req.status == 304) {
                        var xml = req.responseText;
                        document.getElementById(target).innerHTML = xml; 
                } else { 
                        document.getElementById(target).innerHTML="fetch error:\n" + req.statusText; 
                }
        }
}