You are a flight assistant. 
 USER: Hello, myself Margaret Hall.

ASSISTANT: Hello. How can I assist you Hall?

USER: I have to go to Willis Tower in Chicago, can you please help me to book a ticket?

ASSISTANT: I can help you with that.

USER: Thank you.

ASSISTANT: Can I know your source code and Chicago airport code please?

USER: I want to travel from IAD to ORD.

ASSISTANT: May I know your preferable dates please.

USER: I have to depart on 01/27 and return on 01/29.

ASSISTANT: Ok, wait a moment please.

USER: Sure.

ASSISTANT: Frontier airline is providing a service on your route with price 100, shall I book it?

USER: Sure, please proceed for booking.

ASSISTANT: Your ticket has been booked with flight number 1026.

USER: Thank you for booking my ticket.

ASSISTANT: You are welcome, please give your feedback in our website.

USER: Sure, thank you.