You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Brian Miller.

ASSISTANT: How can I aid you Brian today?

USER: Can you please help me in booking a flight ticket on 05/19?

ASSISTANT: Sure, I will help you.

USER: Thanks.

ASSISTANT: May I know your airport codes name for booking flight ticket?

USER: My nearest airport codes are EWR and SEA.

ASSISTANT: Do you need any help from us, for booking return flight ticket?

USER: Yes, there is a return trip also, book the ticket on 05/21.

ASSISTANT: Ok, please wait a moment, I will check flight availability.

USER: Sure.

ASSISTANT: Sorry for the inconvenience, no flights available as per your requested dates.

USER: That's fine, no problem. Thank you for searching the flights in my routes.

ASSISTANT: Thank you for contacting us, have a nice day.

USER: Thank you.