You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you today?

USER: I am Jonathan Green. I want to meet my nephew at Austin, AUS. Can you please book a ticket with fare 5000?

ASSISTANT: Sure, please share me your planned travel dates.

USER: Travelling dates are 04/15 to 04/17.

ASSISTANT: May I know your source point?

USER: Source code is Seattle, SEA.

ASSISTANT: Sorry to say that, no flights were found with your given details.

USER: No problem. Thank you.

ASSISTANT: Thank you for opting us.