JQuery EasyUI combobox动态添加option

<input class="easyui-combobox" id="rwlb" name="rwlb" style="width:435px" data-options="valueField:'id', textField:'text', panelHeight:'auto'" >  

方法一：

1 var data, json;
2 json = '[{"id":"年计划","text":"年计划","selected":true}]';
3 data = $.parseJSON(json);
4 $("#rwlb").combobox("loadData", data);

方法二：

1 var data,json;
2 data = [];
3 data.push({ "text": "测试", "id": 100 });
4 $("#rwlb").combobox("loadData", data);

<%@ WebHandler Language="C#" Class="Handler" %>
using System;
using System.Web;
using System.Collections;
using System.Collections.Generic;
using System.Web.Script.Serialization;
public class Handler : IHttpHandler {    
    public void ProcessRequest (HttpContext context) {
        JavaScriptSerializer jss = new JavaScriptSerializer();
        context.Response.ContentType = "text/plain";
        List<Dictionary<string, string>> _list = new List<Dictionary<string, string>>();
        Dictionary<string, string> drow = new Dictionary<string, string>();
        drow.Add("name", "Wang");
        drow.Add("age", "24");
        Dictionary<string, string> drow1 = new Dictionary<string, string>();
        drow1.Add("name", "Zhang");
        drow1.Add("age", "35");
        _list.Add(drow); 
        _list.Add(drow1);   
        context.Response.Write(jss.Serialize(_list));               
    } 
    public bool IsReusable {
        get {
            return false;
        }
    }
}