how to implement custom grouping in jqGrid

I'm starter in jqGrid, i write this code for Implement Grouping

$(function () {
            var mydata = [
                          { id: "11", invdate: "2007-10-01", name: "test", note: "note", amount: "200.00", tax: "10.00", total: "210.00" },
                          { id: "12", invdate: "2007-10-02", name: "test2", note: "note2", amount: "300.00", tax: "20.00", total: "320.00" },
                          { id: "13", invdate: "2007-09-01", name: "test3", note: "note3", amount: "400.00", tax: "30.00", total: "430.00" },
                          { id: "14", invdate: "2007-10-04", name: "test", note: "note", amount: "200.00", tax: "10.00", total: "210.00" },
                          { id: "15", invdate: "2007-10-05", name: "test2", note: "note2", amount: "300.00", tax: "20.00", total: "320.00" },
                          { id: "16", invdate: "2007-09-06", name: "test3", note: "note3", amount: "400.00", tax: "30.00", total: "430.00" },
                          { id: "17", invdate: "2007-10-04", name: "test", note: "note", amount: "200.00", tax: "10.00", total: "210.00" }, 
                          { id: "18", invdate: "2007-10-03", name: "test2", note: "note2", amount: "300.00", tax: "20.00", total: "320.00" },
                          { id: "19", invdate: "2007-09-01", name: "test3", note: "note3", amount: "400.00", tax: "30.00", total: "430.00" },
                          { id: "21", invdate: "2007-10-01", name: "test", note: "note", amount: "200.00", tax: "10.00", total: "210.00" },
                          { id: "22", invdate: "2007-10-02", name: "test2", note: "note2", amount: "300.00", tax: "20.00", total: "320.00" },
                          { id: "23", invdate: "2007-09-01", name: "test3", note: "note3", amount: "400.00", tax: "30.00", total: "430.00" }, 
                          { id: "24", invdate: "2007-10-04", name: "test", note: "note", amount: "200.00", tax: "10.00", total: "210.00" },
                          { id: "25", invdate: "2007-10-05", name: "test2", note: "note2", amount: "300.00", tax: "20.00", total: "320.00" },
                          { id: "26", invdate: "2007-09-06", name: "test3", note: "note3", amount: "400.00", tax: "30.00", total: "430.00" },
                          { id: "27", invdate: "2007-10-04", name: "test", note: "note", amount: "200.00", tax: "10.00", total: "210.00" },
                          { id: "28", invdate: "2007-10-03", name: "test2", note: "note2", amount: "300.00", tax: "20.00", total: "320.00" },
                          { id: "29", invdate: "2007-09-01", name: "test3", note: "note3", amount: "400.00", tax: "30.00", total: "430.00"}];
            jQuery("#list48").jqGrid({
                data: mydata,
                datatype: "local",
                height: 'auto',
                rowNum: 30,
                rowList: [10, 20, 30],
                colNames: ['Inv No', 'Date', 'Client', 'Amount', 'Tax', 'Total', 'Notes'],
                colModel: [
                    { name: 'id', index: 'id', width: 60, sorttype: "int" },
                    { name: 'invdate', index: 'invdate', width: 90, sorttype: "date", formatter: "date" },
                    { name: 'name', index: 'name', width: 100, editable: true },
                    { name: 'amount', index: 'amount', width: 80, align: "right", sorttype: "float", formatter: "number", editable: true },
                    { name: 'tax', index: 'tax', width: 80, align: "right", sorttype: "float", editable: true },
                    { name: 'total', index: 'total', width: 80, align: "right", sorttype: "float" },
                    { name: 'note', index: 'note', width: 150, sortable: false}],
                pager: "#plist48",
                viewrecords: true,
                sortname: 'name',
                grouping: true,
                groupingView: { groupField: ['name'] },
                caption: "Grouping Array Data" });

        });

and create this grid

i want set Grouping Dynamicaly.Such that user Drag Header Column and Drop in top box after that grid Grop such this picture please help me for implement this senaryo . thanks all

On the jqGrid side you need to use groupingRemove and groupingGroupBy methods to change grouping dynamic, you can read more about them in documentation.

For the UI part you should look at following interactions:

Draggable
Droppable
Sortable

The Shopping Cart sample in Droppable should give you a very good overview on how to approach the subject.

Now after all that theoretical informations, I have created a sample on jsFiddle for you: jqGrid dynamic drag-n-drop grouping. It needs some styling to look exactly as what you are looking for, but it should allow you to understand all the internals. If you need some comments on the code let me know - I can add them later.