You are a flight assistant. 
 USER: Hi. I am Andrew Lee.

ASSISTANT: Hello, how may I assist you at present?

USER: I have a plan to go for beer festival at Las Vegas, please book a flight ticket under price 200.

ASSISTANT: Sure, please share your journey dates.

USER: My travelling dates are from 10/12 to 10/14.

ASSISTANT: Ok, From where do you want to deviate?

USER: I want to fly from IAD, Washington.

ASSISTANT: Ok, please help me with Las Vegas airport code.

USER: My destination code is LAS.

ASSISTANT: Ok, please wait for a while.

USER: Ok, take your time.

ASSISTANT: Thanks for your time, we found a flight in 1029 Southwest airline with a fare of 100.

USER: Please go with booking.

ASSISTANT: Sure, your booking has been done.

USER: Thanks for the reservation.

ASSISTANT: Thank you for reaching us.