You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I aid you today?

USER: I want to do some changes in existing reservation. Can you help me for that?

ASSISTANT: Sure, I am here to help you with that. May I know your name please?

USER: My name is Robert Wright.

ASSISTANT: Robert Wright, I have found your previous reservation. Can you please share your preferable travel dates?

USER: My travelling dates are June 16 and June 18.

ASSISTANT: May I know your new source and destination codes to proceed for further?

USER: My travelling airport codes are SFO and LAS.

ASSISTANT: Do you need a connecting flight or direct flight?

USER: I need a single connecting flight in my journey.

ASSISTANT: Is there any class preference?

USER: Any class is fine for me.

ASSISTANT: American Airlines are providing a flight with single connection limit with a fare of 100. Shall I proceed with booking?

USER: Ok, proceed for booking.

ASSISTANT:  Robert Wright, your booing is done in economy class, the depart time is 7:00 AM and return time is 12:00 PM.

USER: Thank you for booking.

ASSISTANT: Mot welcome, thank you for reaching us. Have a safe journey.

USER: Welcome.