jQuery Grid search function not working

jQuery Grid search function not working

hi,

search function is not working i want multisearch function please check my code below

jQuery(document).ready(function () {
            $('#btn1').click(function () {
                //debugger;
                $("#grid").jqGrid({
                    url: 'WebMethodEx.aspx/GetDataFromDB',
                    datatype: 'json',
                    mtype: 'POST',
                    ajaxGridOptions: { contentType: 'application/json; charset=utf-8' },
                    data:'{}',
                    serializeGridData: function (postData) {
                        return JSON.stringify(postData);
                    },
                    jsonReader: {
                                             page: function (obj) { return 1; },
                                             total: function (obj) { return 1; },
                                             records: function (obj) { return obj.d.length; },
                                             root: function (obj) { return obj.d; },
                                             repeatitems: false,
                                             id: "0"
                                         },
                    colModel: [
                                { key: false, name: 'UserName', index: 'UserName', editable: false, searchoptions: { sopt: ['eq', 'ne', 'lt', 'le', 'gt', 'ge'] } },
                                { key: false, name: 'FirstName', index: 'FirstName', search: false, searchoptions: { sopt: ['eq', 'ne', 'lt', 'le', 'gt', 'ge'] } },
                                { key: false, name: 'LastName', index: 'LastName', search: false, searchoptions: { sopt: ['eq', 'ne', 'lt', 'le', 'gt', 'ge'] } },
                                { key: false, name: 'Address1', index: 'Address1', searchoptions: { sopt: ['eq', 'ne', 'lt', 'le', 'gt', 'ge'] } },
                                { key: false, name: 'City', index: 'City', editable: false, searchoptions: { sopt: ['eq', 'ne', 'lt', 'le', 'gt', 'ge'] } }
                    ],
                    rowNum: 5,
                    rowList: [10, 20, 30],
                    pager: "#pager",
                    viewrecords: true,
                    gridview: true,
                    rownumbers: true,
                    height: 230,
                    caption: 'User List'
                    //, search: true
                }).jqGrid('navGrid', '#pager', { edit: true, add: true, del: false, Search: true },
                {
                    // edit options
                  
                },
        {
            // add options
           
        },
        {
            // delete options
         
        },
        {
            closeAfterSearch: true,
            closeAfterReset: true,
            closeOnEscape: true,
            multipleSearch: true,
            sopt: ['eq', 'ne', 'cn', 'bw'],
            onSearch: function () {
                debugger;
                $('#grid').jqGrid('setGridParam', { datatype: 'json' }).trigger('reloadGrid');
            },
            onReset: function () {
                $('#grid').jqGrid().trigger('reloadGrid');
            }
        }

                );
            });
        });