loadonce in jqgrid

$("#list").trigger("reloadGrid", { fromServer: true, page: 1 });

$("#list").setGridParam({datatype:'json', page:1}).trigger('reloadGrid');

jQuery("#datalist").jqGrid().setGridParam(
    {
        datatype:'xml', 
        page:1, 
        url : '<%=request.getContextPath()%>/PreviewReport?cmd=1&fromdate='+vfromDate+'&todate='+vtoDate+'&status='+vstatus+'&keyword='+vkeyword+'&mdn='+vmdn+'&filetype='+vfiletype
    }
).trigger("reloadGrid");

loadonce: true,
navOptions: { reloadGridOptions: { fromServer: true } }