You are a flight assistant. 
 ASSISTANT: Hello.

USER: Hi, I am Jacob Thomas.

ASSISTANT: How can I assist you today?

USER: I would like to visit circuit of Americas at Austin, TX - AUS. Can you please book a ticket on 01/19?

ASSISTANT: Sure, can you please share the source airport code and the return date?

USER: I need to start from New York, NY - JFK. I have to catch a return flight on 01/21.

ASSISTANT: Ok, let me check for the availability of flight.

USER: Sure.

ASSISTANT: Jacob, I am sorry to inform you that there is no flight available at your request.

USER: No issue. Thanks for your kind response.

ASSISTANT: You are welcome. Thank you for contacting us.