*/
public void updateTimeServer(String timeServer, Boolean useTimeServer) throws PageException {
checkWriteAccess();
if(useTimeServer!=null && useTimeServer.booleanValue() && !StringUtil.isEmpty(timeServer,true)) {
try {
new NtpClient(timeServer).getOffset();
} catch (IOException e) {
throw new ExpressionException("invalid timeserver (NTP) ["+timeServer+"] ");
}
}