jqgrid grouping

HTML

<link rel="stylesheet" href="http://ajax.googleapis.com/ajax/libs/jqueryui/1.8.14/themes/base/jquery-ui.css">
<link rel="stylesheet" href="http://trirand.com/blog/jqgrid/themes/ui.jqgrid.css">
<script src="http://trirand.com/blog/jqgrid/js/i18n/grid.locale-en.js"></script>
<script src="http://trirand.com/blog/jqgrid/js/jquery.jqGrid.js"></script>

JavaScript 1.7

jQuery(function () {

    data = [
		{ groupId: 2, groupName: "Daily Evening Reports", reportId: "18", lastReportVersion: "140717", lastGenerated: "#2013,12,5,16,38,31,40", myReport: true, fileExt: "pdf", name: "Trading Package NYSE", displayOrder: 1 }
, { groupId: 2, groupName: "Daily Evening Reports", reportId: "19", lastReportVersion: "140718", lastGenerated: "#2013,12,5,16,38,32,463", myReport: false, fileExt: "pdf", name: "Trading Package OTC", displayOrder: 2 }
, { groupId: 2, groupName: "Daily Evening Reports", reportId: "481", lastReportVersion: "140732", lastGenerated: "#2013,12,5,16,42,36,727", myReport: false, fileExt: "pdf", name: "Trading Package Japan", displayOrder: 3 }
, { groupId: 1, groupName: "Daily Morning Reports", reportId: "1", lastReportVersion: "140648", lastGenerated: "#2013,12,5,6,20,2,597", myReport: false, fileExt: "pdf", name: "International Interest Rates (Morning)", displayOrder: 1 }
, { groupId: 1, groupName: "Daily Morning Reports", reportId: "2", lastReportVersion: "140649", lastGenerated: "#2013,12,5,6,20,10,387", myReport: true, fileExt: "pdf", name: "International Market Indices (Morning)", displayOrder: 2 }
, { groupId: 1, groupName: "Daily Morning Reports", reportId: "3", lastReportVersion: "140650", lastGenerated: "#2013,12,5,6,20,10,677", myReport: false, fileExt: "pdf", name: "Commodities (Morning)", displayOrder: 3 }
, { groupId: 11, groupName: "User Custom Reports", reportId: "61", lastReportVersion: "140652", lastGenerated: "#2013,12,5,6,22,2,470", myReport: false, fileExt: "pdf", name: "Composite Report (Morning)", displayOrder: 1 }
, { groupId: 11, groupName: "User Custom Reports", reportId: "67", lastReportVersion: "140704", lastGenerated: "#2013,12,5,12,58,51,577", myReport: false, fileExt: "pdf", name: "Intraday CGS Report", displayOrder: 2 }
, { groupId: 11, groupName: "User Custom Reports", reportId: "60", lastReportVersion: "140707", lastGenerated: "#2013,12,5,16,32,0,43", myReport: false, fileExt: "pdf",...