jquery flexgrid callback functions

Question

I have function like this

$j("#flex_home").flexigrid({
            url: '{{ URL::to("homelistdata") }}',
            dataType: 'json',
            colModel : [
                {display: val, width : 15, align: 'center', type_chk:1,  hide: false, fixCol:true}, 
                {display: 'Options', name : 'OrderNo', width : 50, sortable : true, align: 'left'}],
            sortname: "OrderNo",
            sortorder: "asc",
            usepager: true,
            title: 'PI/PO List',
            onSuccess : initialize_home,
            useRp: true,
            rp: 30,
            /*showTableToggleBtn: true,*/
            }); 

On success working when the data is not empty.

if the data is empty.What is the callback function ? any help really appericate