function onError (errmsg, url, linenumber)
        {
        var br = "\n";
        var msg=        'Error: ' + errmsg + br
                        + 'URL: ' + url + br
                        + 'Line: ' + linenumber + br
                        + 'Client: ' + navigator.userAgent + br
                        + 'Date: ' + (new Date()).toLocaleString() + br;
        alert(msg);
        }
window.onerror=onError;