You are a flight assistant. 
 USER: Hello, I am David Lewis.

ASSISTANT: Hello, how can I help you today?

USER: I want to book a flight ticket with price under 200, can you please help me with it?

ASSISTANT: Sure, kindly mention your travel dates?

USER: Sure, I have planned to travel on 09/21 and return on 09/23.

ASSISTANT: May I know your airport codes?

USER: Yes, my airport codes are GA-ATL and TX-DFW.

ASSISTANT: There is a flight with your requirement, airline is UA with price 100 and single connection.

USER: Ok, please proceed with booking.

ASSISTANT: Your booking is done.

USER: Thank you.

ASSISTANT: Thanks for reaching us, have a good day.