You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you?

USER: John Martinez this side, I want to book a ticket to Charlotte for giving an audition. Can you help me to book a ticket?

ASSISTANT: Sure, may I know your unique airport codes please?

USER: I am looking to travel from DEN to CLT.

ASSISTANT: Ok, may I know your travel dates please?

USER: I am looking to start my journey on 11/21 and end on 11/23.

ASSISTANT: Ok, hold on for a moment. Let me check.

USER: Ensure that price limit is 200.

ASSISTANT: I found a flight for you with AA airline and it costs you 100. Shall I proceed?

USER: Please book it.

ASSISTANT: Your ticket has been booked with 1024 flight number.

USER: Thank you for booking.

ASSISTANT: Welcome.