问如何让Spine.js Ajax持久性工作

EN

<script type="text/javascript" src="/appLib/jquery-1.7.js"></script>
<script type="text/javascript" src="/appLib/spine/spine.js"></script>
<script type="text/javascript" src="/appLib/spine/ajax.js"></script>

<script type="text/javascript">
    jQuery(document).ready(function() {

       Spine.Model.host = "http://localhost:8080/services/api/myservice";

        var Person = Spine.Model.sub();
        Person.configure("firstName", "lastName");
        Person.extend("Spine.Model.Ajax");

        // these callbacks are never called
        Person.bind("refresh", function() {alert("refreshed "+Person.count());});  // never called
        Person.bind("ajaxSuccess", function() {alert("ajax success");});           // never called
        Person.bind("ajaxError", function(record, xhr, settings, error) {
            alert("ajaxError"+error);                                              // never called
        });


        Person.fetch(function() {alert("Fetch "+Person.count());});    // 0
        Person.each(function() {alert("Found");});                     // never called


        // but this direct ajax call works fine
        jQuery.getJSON(Spine.Model.host + "/persons", function(result) {           
            for (var i=0, l=result.length; i<l; i++)  {
                var person = Person.init(result[i]);
                person.save();
            }
            alert(Person.count());   // shows correct result
            Person.each(function(p) {alert(p.lastName);});  // shows correct results
        });


    });
</script>