How to apply dynamically colNames and colModel in Jqgrid using MVC 4.0

I'm working in JqGrid with MVC 4.0 application. How to dynamically set the column names which comes from controller. I want to set the colModel and colnames dynamically. not with static values. kindly me on this.

 var grid = new JqGridObject()
            {
                Page1 = page,
                PageSize = 500,
                SortColumn = sidx,
                SortOrder = sord,
                Data = GetData("CRM-SALES"),
                ColumnAry = GetColumn("Input")
            };
             retu Json(grid, JsonRequestBehavior.AllowGet);
             //json1 = json.toJson(grid);

Here is my jqgrid i have tried by myself

         $.ajax({
        type: "POST",
        url: action,

        data: {},

        // contentType: "application/json;charset=utf-8",
        dataType: "json",
        //   processData: true,
        success: function (data, status, xhr) {
            alert('hi');
            var col;

            $.each(colData.ColumnAry, function () {

                alert(this['columame']);
                col.push(this["columame"]);
            });


            $("#myGrid").jqGrid({
                url: '@Url.Action("Search")',
                datatype: 'json',
                myType: 'POST',
                colNames: col,
                colModel: { name: col },

                jsonReader: {
                    root: 'Data',
                    id: 'id',
                    repeatitems: false
                },

                pager: "#myPager",
                width: 'auto',
                height: 'auto',
                rowNum: 100,
                rowList: [10, 25, 50, 100, 250, 500, 1000, 2000, 5000],
                loadonce: true,
                sortable: true,
                sortname: "OrderID",
                sortorder: "desc",
                viewrecords: true,
                gridview: true,
                autoencode: true,
                ignoreCase: true,
                afterInsertRow: function(rowId,data)
                {
                   // jQuery("#myGrid").setCell(rowId, 'status', data.cellvalue, { background: 'red' });

                },
                loadComplete: function (rowId,data)
                {
                    var ids = jQuery("#myGrid").jqGrid('getDataIDs');


                },

                //pager: $('#myPager'),
                // rowNum: 500,

                width: 1280, height: 500,
                //viewrecords: true,
                caption: 'Details'
            });