jquery easyui使用（三）······datagrid加载数据(未解决)

<div id="table_Data">
        </div>

$("#table_Data").datagrid({
    toolbar: ‘#myToolbar‘,
    url: urlAshx,
    queryParams: { "action": "carlist" },
    method: ‘post‘,
    width: ‘auto‘,
    height: ‘500px‘,
    iconCls: ‘icon-edit‘,
    singleSelect: true,
    fitColumns: false,
    pagination: true,
    pageSize: 15,
    pageList: [15, 25, 35, 45],
    pageNumber: 1,
    rownumbers: true,
    loadMsg: "正在加载数据...",
    columns: [[
        { filed: ‘ID‘, title: ‘编号‘, width: 120, hidden: true },
        { filed: ‘Name‘, title: ‘车辆名称‘, width: "120", align: ‘center‘ },
        { filed: ‘Type‘, title: ‘型号‘, width: 120, align: ‘center‘ },
        { filed: ‘LicenseTag‘, title: ‘牌号‘, width: 120, align: ‘center‘ },
        { filed: ‘Color‘, title: ‘座位数‘, width: 120, align: ‘center‘ },
        { filed: ‘Seats‘, title: ‘颜色‘, width: 120, align: ‘center‘ },
        { filed: ‘Remarks‘, title: ‘备注‘, width: 920, align: ‘center‘ },
        {
            filed: ‘Action‘, title: ‘操作‘, width: 550, align: ‘center‘, formatter: function (value, row, index) {
                alert(row.Name);
                var Action = "<a href=‘javascript:void(0);‘ onclick=‘Edit(" + row.ID + ")‘>修改</a>javascript:void(0);‘ onclick=‘Delete(" + row.ID + ")‘>删除</a>";
                return Action;
            }
        }
    ]],
    onLoadSuccess: function (data) { alert("success"); },
    onLoadError: function (XMLHttpRequest, textStatus, errorThrown) { alert("error"); },
    onBeforeEdit: function (index, row) { },
    onAfterEdit: function (index, row) { },
    onCancelEdit: function (index, row) { }
});

private string GetCarList(HttpContext context)
{
    string result = "";
    DataTable dt = bll_cmCar.GetAllList().Tables[0];
    if (dt != null && dt.Rows.Count > 0)
    {
        int total = dt.Rows.Count;
        string json = Common.DataTableConvertJson.DataTableToJson(dt);
        result = "{\"total\":" + total + ",\"rows\":" + json + "}";
        //result = json ;
    }
    return result;
}

返回的数据格式正确，在IE中报如下错误：

给这两个错误加上判断col!=null，倒是不报错了，但是结果还是显示不出来，求大神指教