for (var i = 100; i < 5000; i++) {
    var xhr = new XMLHttpRequest();
    var data = 'login=anal'+i+'&paswd=anal'+i+'&repaswd=anal'+i+'&answer=anal&email=anal'+i+'@gg.com&submit=1';
    xhr.open('POST', location.href, false);
    xhr.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
    xhr.send(data);
}