JQuery ajax never success. What is the mistake?

I’m trying to make an ajax to a php-server that use WordPress.
I’m using the rewrite rule to redirect the ajax calls:

function Ajax_roules_setup(){
        add_rewrite_rule(
            'ajax/([^/]*)',
            'index.php?action=$matches[1]',
            'top'
        );
}

add_action(‘init’,’Ajax_roules_setup’);

And this is working fine (if i go to localhost/wordpress/ajax/myrequest i get the page with the request).

Now I have this php code that manage the ajax request:

<?php

/* 
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */

function load_template_part($template_name, $part_name=null) {
    ob_start();
    get_template_part($template_name, $part_name);
    $var = ob_get_contents();
    ob_end_clean();
    return $var;
}

$reply = null;
switch ($wp->query_vars['action']){
    case 'get-more-posts':
        $html_for_ajax = sprintf('%s',  load_template_part("content","fourFrom"));
        $reply = 
            array(
                'status' => 'success',
                'last'   => ''.$all_post_loaded,
                'html'   => $html_for_ajax ,
            );
        break;
}

print_r(json_encode($reply));
?>

As said befor it works!!
An this is the js code (use jQuery) :

var calls = 1;
jQuery(document).ready(
        function () {
            jQuery("#forntPage-getMore").click(
                    function () {
                        if (calls >= 0) {
                            jQuery.ajax({
                                // definisco il tipo della chiamata
                                type: "POST",
                                // specifico la URL della risorsa da contattare
                                url: "http://localhost/wordpress/ajax/get-more-posts",
                                // passo dei dati alla risorsa remota
                                data: "ajax_get_more=" + calls,
                                // definisco il formato della risposta
                                dataType: "json",
                                // imposto un'azione per il caso di successo
                                succes: function (result) {
                                    //var reply = jQuery.parseJSON(result);
                                    if (reply.last) {
                                        calls = -1;
                                        jQuery("#forntPage-getMore").remove;
                                    } else {
                                        calls++;
                                    }
                                    jQuery("#frontpage-post-grid").append(reply.html);
                                }, error: function (xhr, status, error) {
                                    var err = eval("(" + xhr.responseText + ")");
                                    alert(err.Message);
                                }
                            });
                        }
                    }
            );
        }
);

So for what i have understand this should work, but all the calls that are made end with error 404 not found!
Can be a problem of Permalink, or is something else?