jQuery Grid Plugin - jqGrid

I create a grid in with this code:

jQuery("#tablePlaces").jqGrid({
                        datatype: 'xmlstring',
                        datastr: data,
                        height: 450,
                        colNames: ['placeId', 'نام مرکز', 'lat', 'lng', 'imageIcon'],
                        colModel: [
                                { name: 'placeId', index: 'placeId', hidden: true },
                                { name: 'placeName', index: 'placeName', width: 175 },
                                { name: 'lat', index: 'lat', hidden: true },
                                { name: 'lng', index: 'lng', hidden: true },
                                { name: 'imageIcon', index: 'imageIcon', hidden: true }
                        ],
                        viewrecords: true,
                        direction: "rtl",
                        multiselect: false,
                        rowNum: -1,
                        rownumbers: true,
                        caption: "لیست مراکز",
                        viewrecords: false,
                        scrollrows: true,
                        pager: jQuery('#tablePlacesPager'),
                        onSelectRow: function(rowId) {
                            var idd = jQuery("#tablePlaces").getGridParam("selrow");
                            alert(idd);

                         
                        }
                    });

when I use addrowdata method here:

jQuery("#tablePlaces").addRowData(parseInt(num) + 1, {
                            placeId: json.d,
                            placeName: newName,
                            lat: lat,
                            lng: lng,
                            imageIcon: imageIcon
                        }, 'last');

it added the row successfully but when I select the new row, it returns 0 as the number of selected row

what is the problem here? is it a bug?