You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I aid you?

USER: I want to change an existing reservation, so please help me in changing the reservation.

ASSISTANT: May I know your name?

USER: Myself David Carter.

ASSISTANT: Your reservation found, may I know your details?

USER: I want to fly on July 10 and return on July 12.

ASSISTANT: May I know your airport codes?

USER: My airport codes are MCO, SEA.

ASSISTANT: Do you prefer any specifications?

USER: I would like to return in the morning time.

ASSISTANT: There is a connected flight in AA airlines with the fare 200.

USER: You can proceed to booking.

ASSISTANT: May I know your name?

USER: I already mentioned above.

ASSISTANT: Your booking is done.

USER: Thank you.

ASSISTANT: Thank you.