You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you at this moment?

USER: I am Sandra King. I am planning to visit Lady Bird Lake at Austin, could you please help me with booking a flight ticket?

ASSISTANT: Sure, please share your travelling dates.

USER: I would like to take off on 12/21 and return on 12/23.

ASSISTANT: Can I have your nearby airport codes?

USER: My nearest source airport code is LAS and destination airport code is AUS.

ASSISTANT: Please give me a moment.

USER: Sure.

ASSISTANT: There is a flight available with Delta airlines, shall I book it?

USER: Please proceed with the booking if the ticket fare is less than 200.

ASSISTANT: Your booking is done with flight number 1005. Happy journey.

USER: I really appreciate your help, thank you for your service.

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