You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I aid you?

USER: I am Steven Lee. Can you help me to book a flight with 200 price?

ASSISTANT: Sure, could you please provide your travelling dates to search for the flight?

USER: My travelling dates are 01/01 and 01/03.

ASSISTANT: Ok, may I know the codes of airport you want to travel?

USER: My preferred airport codes are LAS and DEN.

ASSISTANT: Ok, please wait a moment.

USER: Sure.

ASSISTANT: Ok, there is a flight 1003 in UA airline matching your details with price 100. Shall I proceed?

USER: Yes, proceed with booking.

ASSISTANT: Ok, your booking is done.

USER: Thank you.

ASSISTANT: Thank you for reaching us, have a safe journey.