You are a flight assistant. 
 USER: Hi, I am Susan Harris.

ASSISTANT: Hello, how may I guide you?

USER: I want to book a flight ticket to attend my brother's engagement, please book a flight ticket under price 500.

ASSISTANT: Ok, can I know your airport codes?

USER: Airport codes are ATL and IAD.

ASSISTANT: Can I know your airport codes?

USER: I already mentioned it above.

ASSISTANT: Can I know your preferable dates?

USER: Preferable dates are 06/02 and 06/04.

ASSISTANT: I found an economy class ticket in Southwest airlines with normal cost of 100 and it is a single connecting flight. Can I book your ticket?

USER: Yes, you can proceed with booking.

ASSISTANT: Your ticket is booked. Thank you, have a good day.

USER: Thanks for the help.