jqgrid 增删改操作问题

页面：
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>
<%@ taglib uri="http://tiles.apache.org/tags-tiles" prefix="tiles"%>
<%@ taglib uri="http://java.sun.com/jsp/jstl/fmt" prefix="fmt"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>   
    <title>首页</title>      
    <script src="${applicationScope.rootpath}js/jquery.js" type="text/javascript"></script>
    <script src="${applicationScope.rootpath}js/jqgrid/js/jquery-1.4.2.min.js" type="text/javascript"></script>
    <script src="${applicationScope.rootpath}js/jqgrid/js/i18n/grid.locale-cn.js" type="text/javascript"></script>
<script src="${applicationScope.rootpath}js/jqgrid/js/jquery.jqGrid.min.js" type="text/javascript"></script>
    <script src="${applicationScope.rootpath}js/jqueryui/js/jquery-ui-1.8.6.custom.min.js" language="Javascript"></script>
    <link   href="${applicationScope.rootpath}js/jqgrid/css/ui.jqgrid.css" rel="stylesheet" type="text/css"/>
    <link  href="${applicationScope.rootpath}js/jqgrid/themes/redmond/jquery-ui-1.8.2.custom.css" rel="stylesheet" type="text/css"/>
     
 <script type="text/javascript">
 var jq=jQuery.noConflict(); 
 jq(document).ready(function(){ 
  jq('#personList').trigger("reloadgrid"); 
jq("#personList").jqGrid({
                url:'${applicationScope.rootpath}test/test_personList.action',
                datatype: "json",
                mtype: "POST",
                height: 'auto',
                colNames:['编号','姓名','年龄'],
                colModel:[     
            
            {name:'ID',index:'ID',width:120,sorttype:"int",formatter:"int"},                        
    {name:'NAME',index:'NAME',width:120,sorttype:"string",editable:true},  
    {name:'AGE',index:'AGE',width:120,sorttype:"int",formatter:"int",editable:true} 
         
    ],
                sortname:'ID',
                sortorder:'asc',                
                viewrecords:true,
                rowNum:10,
                rowList:[10,20,30], 
                onSelectRow: function(ID){ //行点击事件
                 var rowData = jq("#personList").jqGrid("getRowData", ID);
                 var id=rowData.ID;
jq('#personList').jqGrid('editRow',ID,true);
 
}, 
editurl: "${applicationScope.rootpath}test/test_editPerson.action",//定义操作的路径
                caption: "可编辑的表格",
                pager: '#ppersonList', //定义翻页div
                loadonce:true,
                jsonReader: {
                        root:"rows",                // 数据行（默认为：rows）
                        repeatitems : false         // 设置成false，在后台设置值的时候，可以乱序。且并非每个值都得设
                }               
                        
});
//设置底部的按钮状态
jq("#personList").jqGrid('navGrid',"#ppersonList",{edit:true,add:true,del:true,search:true,view:false});
 
}); </script>
</head>
  
  <body>
     操作表<br/>
     <table id="personList"></table>
<div id="ppersonList"></div>
<!-- 
<input type="button" id="btnAdd" value="Add"/>
<input type="button" id="btnEdit" value="Edit"/>
<input type="button" id="btnDel" value="Del"/>
 -->
  </body>
</html>
action:
public String personList(){
List<Person> personList=this.service.findAll();
JSONObject obj = new JSONObject();      
    JSONArray lineitemArray = new JSONArray();
    for(Person p:personList){
      JSONObject o = new JSONObject();       
      o.put("ID",p.getId());
      o.put("NAME",p.getName());
      o.put("AGE",p.getAge());  
      o.put("PID",p.getId());
      lineitemArray.add(o);
    }
    obj.put("rows", lineitemArray);    //具体的Table显示内容
    String jsonStr  = JSONObject.fromObject(obj).toString();
setTextAjax(jsonStr);
return HTML;

}

public String editPerson(){
System.out.println(id+"+++++++"+oper);
 if(oper != null && oper.equals("edit")){ //修改
    Person p=this.service.findById(this.id);
p.setName(this.NAME);
p.setAge(this.AGE);
this.service.update(p);
 } 
 if(oper != null && oper.equals("add")){ //添加
    Person p=new Person();
p.setName(this.NAME);
p.setAge(this.AGE);
this.service.add(p);
 } 
 if(oper != null && oper.equals("del")){ //删除
  Person p=this.service.findById(this.id);
  this.service.del(p);
 } 
return personList();
}
修改和删除是按table的行号进行的，但我需要获得是编号啊？？？？