easyui翻页后修改datagrid 报错 Cannot read property 'ck' of undefined

[code=html
<html>
  <head>
    <base href="<%=basePath%>">
    
    <title></title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<link rel="stylesheet" href="duowei/css/style.css" type="text/css"></link> 
 
<script src="duowei/js/main.js"></script>
<script src="duowei/js/echar.js"></script> 
<script type=text/javascript src="duowei/js/jquery-1.4.3.min.js"></script>
<%@include file="/common/jquery_easyui_include.jsp"%>
<script type="text/javascript" src="<%=basePath %>js/lhgdialog/lhgdialog.min.js?skin=jtop"></script>
  </head>
 
 <body onload="onload()"  class="easyui-layout"  >
<input type="hidden" id="currentCityId" value="${sessionScope.current_area_id}">
<input type="hidden" id="currentCityName" value="${sessionScope.current_city_Name}">
<input type="hidden" id="currentZoneNumber" value="${sessionScope.current_zone_Number}">
<div   class="city-box">
    <div style="margin-top:2px;width:100%;height:45px;padding-top:30px;padding-left:15px;">
      
            &nbsp;&nbsp;&nbsp;所属城市:
<select id='selectCity' name='selectCity' onchange="changeArea()" style="border-right:1px solid #E6E8EA" >
<option selected="selected"  value="-1">所属城市</option>
<c:forEach items="${sessionScope.areaList}" var="area">
<option <c:if test="${sessionScope.current_area_id==area.AREA_ID}">selected="selected" </c:if> value="${area.AREA_ID}" valueZoneNumber="${area.ZONE_NUMBER}" extent="${area.KEYVALUE}" >${area.NAME}</option>
</c:forEach>
</select>
          
         
          &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<input  type="button"  id = "exportId"  value="评估" onclick=" autoEvaluation()" style="border: 1px solid #EED2EE;height: 25px;background-color: rgb(229, 234, 245)">
          &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<input  type="button"  id = "exportId"  value="批量评估" onclick=" autoBatchEvaluation()" style="border: 1px solid #EED2EE;height: 25px;background-color: rgb(229, 234, 245)">
         
    </div>
    <div style="margin-top:2px;width:100%;height:45px;padding-left:15px;">
    
    </div>
   
    <div id="bztff" style="width:98%;height:90%;margin-top:10px;margin-left:4px">
<div class="easyui-panel" style="width:90%; height:85%;margin-left:20px">
  <table id="communityList" style="width:95% "   >
       <thead>
        <tr>
            <th field="ck" checkbox="true" ></th>
            <th data-options="field:'SHENG_NAME'" style="width:15%;" >省份</th>
           <th data-options="field:'CITYID'" style="width:15%;">城市id</th>
            <th data-options="field:'CITY_NAME'" style="width:15%;">城市名称</th>
               <th data-options="field:'AREA_NAME'" style="width:15%;">行政区</th>
                <th data-options="field:'XQID'" style="width:15%;">小区ID</th>
                 <th data-options="field:'COMMUNITY_NAME'" style="width:15%;">小区名称</th>
                  <th data-options="field:'ADDRESS'" style="width:15%;">小区地址</th>
                   <th data-options="field:'message'" style="width:15%;">评估信息</th>
                    <th data-options="field:'unitprice'" style="width:15%;">unitprice</th>
                     <th data-options="field:' zxd'" style="width:15%;">zxd</th>
                      <%--<th data-options="field:'AREA_NAME'" style="width:15%;">行政区名称</th>--%>
                       <%--<th data-options="field:'TOTALFLOOR'" style="width:15%;">总楼层</th>--%>
                      <%--<th data-options="field:'msg'" style="width:15%;">评估结果</th>--%>         </tr>
        </thead>
    </table>
</div>
</div>
</div>

 
  </body>
  <script type="text/javascript" >      /**
       * 自动评估
       */
      var autoEvaluation=function(){
          //得到一行数据
          var row = $('#communityList').datagrid('getSelected');
          var rowIndex = $("#communityList").datagrid('getRowIndex', row);
          var ADDRESS1 =encodeURI( row.ADDRESS);
          var AREA_NAME1 =encodeURI( row.AREA_NAME);
          var COMMUNITY_NAME1 =encodeURI(row.COMMUNITY_NAME);
          // alert(row.code);
          console.log(row);
          //调用自动评估接口
          $.ajax({
              url : "AutoEvaluationController/AutoEvaluation.do",
              dataType:'json',
              data : {"ADDRESS":ADDRESS1,"AREA_NAME":AREA_NAME1,"COMMUNITY_NAME":COMMUNITY_NAME1},
              type:'post',
              async : false,
              success :function(data){
                  // alert(data.message+";评估价格："+ data.unitprice);
                  var _msg = data.message+"; ";
                  if(data.code=='0') {
                      _msg += "评估价格:"+ data.unitprice;
                  }
                  $('#communityList').datagrid('updateRow',{index: rowIndex, row: {
                      message:data.message,
                      unitprice: data.unitpridace,
                      zxd:data.zxd
                  }});
              }});      }
      /**
       * 批量自动评估
       */
      var autoBatchEvaluation=function(){
          $('#communityList').datagrid("reload")
          //得到数据
          var row = $('#communityList').datagrid('getSelections');
          if(row.length<1){
              alert("请选中至少一行数据");
              return;
          }
          var $d =$('#communityList');          var rowResult =JSON.stringify(row);
          //alert(rowResult);
          //调用自动评估接口
          $.ajax({
              url : "AutoEvaluationController/batchValuation.do",
              dataType:'json',
              data :rowResult ,
              type:'post',
              async : false,
              contentType : 'application/json;charset=utf-8',
              success :function(data){
                  for (var i =0;i<data.length;i++){                      $d.datagrid('updateRow',{index: (data[i].rn)-1, row: {
                          message:data[i].message,
                          unitprice: data[i].unitprice,
                          zxd:data[i].zxd,
                      }});                  }
//                 $('#communityList').datagrid('clearSelections');
              }})      }
      var cityid=$("#selectCity").val();
      var areid=-1;
      function changeArea(){
          cityid= document.getElementById("selectCity").value;          if(cityid.indexOf("select")>0){
              cityid=cityid.substring(0,cityid.indexOf("sele"));
          }
          $("#citySelect1").empty();
          getAreas();
          areid= document.getElementById("citySelect1").value;          // getdata();
          getdangerYapin(cityid,areid);
      }      //分页查询
      function getdangerYapin (cityid,areid){
          var zonenumber=$("#selectCity").find("option:selected").attr("valueZoneNumber");
          zonenumber=zonenumber.substring(0,4);
          $('#communityList').datagrid({
              title:"",
              ///iconCls:"icon-edit",//图标
              width: "100%",
              height: "auto",
              nowrap: false,
              striped: false,
              border: false,
              fit:true,
              pageSize: 15,
              pageList:[15, 25, 50],
              collapsible:false,//是否可折叠的
              url:"AutoEvaluationController/searchAutoE.do",
              remoteSort:false,
              queryParams:{
                  cityId:cityid,
                  areid: areid,
                  zoneNumber:zonenumber
              },
//         idField:'fldId',
              pagination:true,//分页控件
              rownumbers:false,//行号
              method:'post'
          });   $('#communityList').datagrid('loadData', { total: 0, rows: [] });//清空下方DateGrid      }      function getdata(){
          areid= document.getElementById("citySelect1").value;
          getdangerYapin (cityid,areid);
      }      function getAreas(){
          cityid= document.getElementById("selectCity").value;
          $("#citySelect1").empty();
          $.ajax({
              url : "address/getListAreaYp.do",
              dataType:'json',
              data : {"cityid":cityid},
              type:'post',
              async : false,
              success :function(areas){
                  if(areas){
                      var html = "<option value = \"-1\" selected=\"selected\">行政区</option>";
                      var l = areas.length;
                      for(var i = 0;i<l;i++){
                          var area = areas[i];
                          if(area.NAME=="市辖区"){
                              continue;
                          }
                          html += "<option value=\""+area.AREA_ID+"\">"+area.NAME+"</option>";
                      }
                      $("#citySelect1").html(html);
                  }else{                  }              }});
          getdata();
      }      function onload(){          getAreas();
          //getdata();
      }
  </script>
</html>
[/code]
第一页 可以实现点击批量评估显示红框内数据  
一旦翻页后再点击 就会报错Uncaught TypeError: Cannot read property 'ck' of undefined
求教大神们 怎么办