You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. What can I do for you today?

USER: I am Andrew Williams. I would like to meet my family in Austin. Can you please book a ticket  for me?

ASSISTANT: Williams, can you please provide us your journey dates?

USER: I am planning to travel on 02/24 and return on 02/26.

ASSISTANT: Ok, may I know your source and destination airport codes?

USER: My nearest source airport codes is EWR and destination airport codes is  AUS.

ASSISTANT: Please wait for a moment, let me check.

USER: Sure, take your own time.

ASSISTANT: I am sorry to say you that there is no flight available on your preferred dates.

USER: That's fine. Thank you for your help.

ASSISTANT: Thank you for contacting us and have a good day.