easyui 带参数的datagride

 <table id="tt" style="100%;height:355px"
                   url="../aowei/Handler/HandlerProjectTrackingList.ashx?ProTrackFlag=Detail"

 title="跟踪<img src='assets/img/21plus_roundel.png' style='16px;height:16px;margin-left:88%;vertical-align: middle;' />
<a href='#' style='color: black;margin-left: 10px'>增加</a>" iconCls="icon-edit"    singleSelect="true" idField="itemid" fitColumns="true" striped="true" >
                    <thead>
                        <tr>
                            <th field="ProTrackTime" width="60"align="center">时间</th>
                            <th field="ProTrackName" width="80" align="center">姓名</th>
                            <th field="ProTrackWay" width="80" align="center" >方式</th>
                            <th field="ProTrackRemark" width="180"align="center" >备注</th>
                            <th field="ProTrackOpeation" width="190" align="center" >操作</th>
                        </tr>
                    </thead>
                </table>

 <script>
        var url = window.location.href;
        var entity = {};
        function GetQueryString(name) {
            var reg = new RegExp("(^|&)" + name + "=([^&]*)(&|$)");
            var r = window.location.search.substr(1).match(reg);
            if (r != null) return unescape(r[2]); return null;
        }
        var urlpara = GetQueryString("AllotProId");
        $(document).ready(function () {
            $('#tt').datagrid('load', {
                ProTrackProId: GetQueryString("AllotProId")
            });
        });
 </script>