loadonce in jqgrid
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");