Jstree and rename-Collection of common programming errors

Rename node in my jstree script doesn’t work’s, and J don’t know why, here is my script:

$(function () {
 $("#stworz_powiazanie").click(function () {
 $("#pages-wrapper").jstree("create");
    });
$("#usun_powiazanie").click(function () { 
    if(!confirm("Czy na pewno chcesz usunac te strone?"))return;
    $("#pages-wrapper").jstree("remove"); 
}); 
$("#zmien_nazwe").click(function () {
   $("#pages-wrapper").jstree("rename");
});
$("#cut").click(function () { 
    $("#pages-wrapper").jstree("cut"); 
});
$("#paste").click(function () { 
    $("#pages-wrapper").jstree("paste"); 
});
$("#pages-wrapper").jstree({
 "core" : { "initially_open" : [ "root" ],
            "load_open" :true,
            "animation" :0,
 },
"html_data" : {
            "ajax" : {
            "url" : "./pobierz.php",
            "data" : function (n) {
                return { id : n.attr ? n.attr("id") : 0 };
            }
        }           },
    "plugins" : ["themes","html_data","ui","contextmenu","crrm","types"],
(............)

$("#pages-wrapper").bind("rename.jstree", function (e, data) {
        $.ajax({
                type: "POST",
                url: './server.php',
                 data: {
                "operation" : "rename_node", 
                "id" : data.rslt.obj.attr("id").replace("node_",""),
                "title" : data.rslt.new_name
                }, 
                success : function (r) {
                    if(!r.status) {
                        data.inst.refresh();
                        alert('Zmieniono Nazwe');
                    }
                }
        });
    })
}); 
});

from firebug J have report:

TypeError: obj is undefined return obj.nodeValue;

What is wrong with my script ? Can anyone check this and tell me what is wrong ?