You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I assist you?

USER: I am Charles Martinez. Can you help me to book a flight with 200 price limit?

ASSISTANT: Sure, can you please provide your travelling dates?

USER: My travelling dates are 10/12 and 10/14.

ASSISTANT: May I know your nearest airport codes of travelling?

USER: My airport codes are DEN and OAK.

ASSISTANT: Give me a moment please.

USER: Sure. Yes, proceed with booking.

ASSISTANT: Delta airlines is available on this route with a ticket fare of 100, shall I book your ticket? Charles Martinez, your ticket is booked with flight number 1012.

USER: Thank you.

ASSISTANT: Thank you, have a safe journey.