You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I oblige you today?

USER: William Baker here. I want to attend a Seminar in Detroit. Can you please help me for booking the flight ticket?

ASSISTANT: When are you planning to make your journey?

USER: My travelling dates are 05/11 and 05/13.

ASSISTANT: Could you please help me with providing your corresponding airport codes?

USER: My airport codes are DEN and DTW.

ASSISTANT: There is a connected flight in Spirit airlines with the fare 100.

USER: I would prefer normal cost airline.

ASSISTANT:  There is a connected flight in Delta airlines with the fare 100.

USER: Please proceed for booking the flight ticket.

ASSISTANT: Your booking is done.

USER: Thanks for helping me.

ASSISTANT: Thank you.