You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I amend you?

USER: I am Andrew Davis. I need to book a ticket to meet my friend on 12/19.

ASSISTANT: Ok.

USER: Could you please help me in booking a return ticket on 12/21?

ASSISTANT: Sure. Can I know your airport codes?

USER: My airport codes are LAS and JFK.

ASSISTANT: Do you have any specifications?

USER: Price should not exceed 500.

ASSISTANT: Please, wait for a while. Thank you for waiting, there is a flight available with Delta airline, flight number 1015 with fare 100 and a lay by.

USER: Sure. You can proceed with booking.

ASSISTANT: Your booking has been done.

USER: Thank you for your help.

ASSISTANT: Thank you for reaching us.