Custom group format

There is an opportunity to define the group format
Source
<link rel="STYLESHEET" type="text/css" href="../../codebase/dhtmlxgrid.css">
<link rel="stylesheet" type="text/css" href="../../codebase/skins/dhtmlxgrid_dhx_skyblue.css">
<script  src="../../codebase/dhtmlxcommon.js"></script>
<script  src="../../codebase/dhtmlxgrid.js"></script>
<script  src="../../codebase/dhtmlxgridcell.js"></script>    
<script  src="../../codebase/ext/dhtmlxgrid_group.js"></script>    
 
 
<div id="gridbox" style="width:600px;height:250px;background-color:white;"></div>
<script>mygrid = new dhtmlXGridObject('gridbox');
mygrid.setImagePath("../../codebase/imgs/");
mygrid.setHeader("Sales,Book Title,Author,Price,In Store,Shipping,Bestseller,Date of Publication");
mygrid.setInitWidths("50,150,100,80,80,80,80,200");
mygrid.setColAlign("right,left,left,right,center,left,center,center");
mygrid.setColTypes("dyn,edtxt,ed,price,ch,co,ra,ro");
mygrid.setColSorting("na,str,str,int,int,int,na,na");
mygrid.customGroupFormat = function(text, count) {
    return "Grouped by " + text + ", there are " + count + " related records";
};
mygrid.init();
mygrid.setSkin("dhx_skyblue");
mygrid.loadXML("../common/grid.xml", function() {
    mygrid.groupBy(2);
});</script>