yYou will need to understand that the grid does not support a search at your end (server)

You will need to write your own code at server to perform the search.

We have a examples in PHP, but you can easy understand and translet it in ASP.

Also you may need to look at the demo files which can be downloaded from the Download section.

Regards

var grid = $('#list');
            grid.jqGrid({
                url: 'jQGridHandler.ashx',
                postData: { ActionPage: 'CostTypes', Action: 'Fill' },
                ajaxGridOptions: { cache: false },
               direction: "rtl",

                datatype: 'json',

                height: 490,
                colNames: ['CostId', 'CostNo', 'CostName', 'Remark '],
                colModel: [
                        { name: 'COST_ID', width: 100, sortable: true, search:true, editable: false, hidden: true, key: true, index: 'COST_ID' },
                        { name: 'COST_NO', width: 100, sortable: true, editable: true },
                        { name: 'COST_NAME', width: 350, sortable: true, editable: true },
                        { name: 'REMARK', width: 300, sortable: true, editable: true }

                        ],
                gridview: true,
                rowNum: 30,
                rowList: [30, 60, 90],
                pager: '#pager',
                sortname: 'COST_ID',
                viewrecords: true,
                rownumbers: true
            });
           grid.jqGrid('navGrid', '#pager', { add: false, edit: false, del: true, search: true },
             {},
             {},
             { url: "JQGridHandler.ashx?ActionPage=CostTypes&Action=Delete", reloadAfterSubmit: false },
             { multipleSearch: true});
when click in search icon and show search box when enter text example 
costNo=1
 jqGrid not filter i think this action no work, please help me for implimet search in jqgrid
EDIT 01: when i add 
loadonce: true
 search work but when remove this option search don't work, please help me. thanks