jqgrid postData setGridParam 调用多次时查询条件累加的问题--详情页查询导致的无法在新的页面中查询

  $("#btn_search").click(function () {
            url = "/AMEvents/GetGridJson?evtype=1";
            var $gridList = $("#gridList");
            var posData = $("#searchform").formSerialize()

            $gridList.setGridParam( 
                {
                    url: url,
                    postData: posData
                }
            ).trigger("reloadGrid");


        });

//查询按钮中给定新的url