jqgrid,JSON输入呈现为空

我试图生成一个jqgrid,它从JSON提要填充,从django后端输出。

处理请求的python如下所示:

from django.http import HttpResponse
from django.utils import simplejson
def json_test(request):
    results = {'total':'1',
               'page':'1',
               'records':'2',
               'rows':[{'id':'1','field1':'blah','field2':'bleh'},
            {'id':'2','field1':'bloo','field2':'blum'}]}
    json = simplejson.dumps(results)
    return HttpResponse(json, mimetype='application/json')

所以我要去 http://127.0.0.1:8000/json_test/ 返回以下内容:

{"records": "2", "total": "1", "rows": [{"field2": "bleh", "field1": "blah", "id": "1"}, {"field2": "blum", "field1": "bloo", "id": "2"}], "page": "1"}

jquery代码如下:

<script type="text/javascript">
jQuery(document).ready(function(){ 
  jQuery("#list").jqGrid({
    url:'http://127.0.0.1:8000/json_test/',
    datatype: 'json',
    mtype: 'GET',
    colNames:['field1','field2'],
    colModel :[ 
      {name:'field1', width:55}, 
      {name:'field2', width:90}, 

    ],
    pager: '#pager',
    rowNum:10,
    rowList:[10,20],
    sortname: 'field1',
    sortorder: 'desc',
    viewrecords: true,
    caption: 'Test Grid'
  }); 
}); 
</script>

知道我哪里出错了吗?我试着把这件事简化成一个尽可能简单的案子来确定原因。