I know that NWA employees appreciate the offer of a tip, but I think that if someone has gone out of their way to accomodate you or had done what you think is an excellent job, then ask them for a comment card and fill it out or get their name and send the comment onto "talk to us" at NWA's website. That goes into their file and their superior is also made known of it. That goes a long way come review time $$$$$$$$$$$$.