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) {}
        }
    }
            
function setNewsletter(id, pr) {
    var url = 'http://www.facharzt.de/content/ajax/set_newsletter.php?id=' + escape(id) + '&pr=' + escape(pr); 
    if (!http_request) {
        return false;
    }
    http_request.onreadystatechange = getResponse;
    http_request.open('GET', url, true);
    http_request.send(null);
}

function getResponse() {
    if (http_request.readyState == 4) {
        var resp = http_request.responseXML;
        var settings = resp.getElementsByTagName('settings').item(0);
        var id  = settings.getElementsByTagName('id').item(0).firstChild.nodeValue;
        var st  = settings.getElementsByTagName('st').item(0).firstChild.nodeValue;
        var pr  = settings.getElementsByTagName('pr').item(0).firstChild.nodeValue;
        if (st == '0') {
            nst = '1';
        } else {
            nst = '0';
        }
        var img = pr + id;
        var imgname = '/content/img/' +  pr + '/newsletter_' + st + '.gif';
        document.getElementById(img).src = imgname;
    }
}