jquery.tree 中selectnode的传值问题

麻烦大家指点下面的这段javascript代码中var o 的selectnode是如何得到参数值id, name, value, parentId的？            $(document).ready(function(){//在DOM加载完成时运行的代码
                autoFillSingle($("#search-keywords"));//?
                $("#tabs").tabs();//?
            });
            function load(){
                $("input").val("");//设定文本框的值
                //autoFill($("#search-keywords"));
                o = {    
                    url: "treeview",//请求ThesMgrAction的treeview方法
                    selectnode: function(id, name, value, parentId){
                        $("#addParentId").val(id), $("#modId").val(id), $("#modName").val(name), $("#modSynonyms").val(value), $("#modParentId").val(parentId), $("#delId").val(id), $("#delParentId").val(parentId)
                    }//获得当前值
                };
                $.ajax({
                    url: o.url,
                    type: "POST",//请求方式
                    async: false,//同步请求
                    data: { //发送到服务器的数据
                        id: 0
                    },
                    success: function(treedata){
                        o.data = treedata;
                    }
                });
                
                $("#tree").treeview(o);//?
                $("#add").click(function(){//添加
                    if ($("#addParentId").val() == "") {
                        openmsgdialog("请先选择一个上级节点");
                    }
                    else {
                        $('#dialogAdd').dialog('open');
                    }
                });
                $("#mod").click(function(){//修改
                    if ($("#modId").val() == "") {
                        openmsgdialog("请选择一个关键词");
                    }
                    else 
                        if ($("#modId").val() == 1) {
                            openmsgdialog("顶层节点不能修改");
                        }
                        else {
                            $('#dialogMod').dialog('open');//打开修改对话框
                        }
                });
                $("#del").click(function(){//删除
                    if ($("#delId").val() == "") {
                        openmsgdialog("请选择一个关键词");
                    }
                    else 
                        if ($("#delId").val() == 1) {
                            openmsgdialog("顶层节点不能删除");
                        }
                        else {
                            if (confirm("此操作不可恢复，可能导致系统崩溃，您确定删除吗？")) {
                                $.ajax({
                                    url: "treedel",
                                    type: "POST",
                                    data: {
                                        id: $("#delId").val()
                                    },
                                    success: function(msg){
                                        if (msg.result == 1) {
                                            $("#tree").reflash($("#delParentId").val());
                                        }
                                        else {
                                            openmsgdialog(msg.errMsg);
                                        }
                                    },
                                    error: function(msg){
                                        openmsgdialog("发生未知错误");
                                    }
                                });
                            }
                        }
                    
                });
                $("#dialogAdd").dialog('destroy');
                $('#dialogAdd').dialog({//添加的对话框
                    autoOpen: false,
                    width: 200,
                    height: 300,
                    modal: true,
                    buttons: {
                        '取消': function(){
                            $(this).dialog('close');
                        },
                        '新增': function(){
                            var text = $('#addName'), value = $('#addSynonyms'), thesParentId = $('#addParentId')
                            var tips = $("#dialogAdd .validateTipsl");
                            var bValid = true;
                            bValid = bValid && checkNotNull(text, "关键词名不能为空", tips);
                            if (bValid) {
                                $.ajax({
                                    url: "treeadd",
                                    type: "POST",
                                    contentType: "application/x-www-form-urlencoded;charset=UTF-8",
                                    data: {
                                        text: text.val(),
                                        value: value.val(),
                                        thesParentId: thesParentId.val()
                                    },
                                    success: function(msg){

                                        if (msg.result == 1) {
                                            $("#tree").reflash($("#addParentId").val());
                                            $('#dialogAdd').dialog('close');
                                            
                                        }
                                        else {
                                            updateTips(msg.errMsg, tips);
                                        }
if(msg.fieldErrors!=null){
updateTips(msg.fieldErrors.value, tips);
}
                                    },
                                    error: function(msg){
                                        updateTips("发生未知异常", tips);
                                    }
                                });
                            }
                        }
                    },
                    close: function(){
                        $('#dialogAdd form')[0].reset();
                        $("#dialogAdd").children().removeClass("ui-state-error");
                        $("#dialogAdd .validateTipsl").text("");
                    }
                })