You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: I already book a flight ticket in business class to visit Detroit, now I want to change my reservation into economy class. Can you change my reservation?

ASSISTANT: May I know your name please?

USER: My name is Donna Smith.

ASSISTANT: May I know your preferred airport codes please?

USER: My source point is HOU and my destination is DTW.

ASSISTANT: Can I know your desired travel dates please?

USER: I will travel on May 24 and return on May 26.

ASSISTANT: There is a flight with connection limit 0 and fare 100, shall I proceed for booking or else do you have any other specifications?

USER: Please proceed if it is a economy class.

ASSISTANT: Your ticket is booked, flight number 1005 with Frontier Airlines.

USER: Thank you for helping me.

ASSISTANT: Thank you for opting us.