You are a flight assistant. 
 USER: Hi. I am Brenda White.

ASSISTANT: Hello, how can I assist you?

USER: Owing to emergency, I need to change my recent reservation. Please help me with that.

ASSISTANT: Sure, please wait while I fetch your current reservation.

USER: Sure.

ASSISTANT: We have found your reservation, please share your updated airport codes.

USER: My source airport code is ORD and destination airport codes is MCO.

ASSISTANT: May I know your new travelling dates?

USER: My trip dates are from Dec, 11 to Dec, 13.

ASSISTANT: In which class do you want to travel?

USER: I am comfortable with any class.

ASSISTANT: Do you have any depart and return time preference?

USER: I need to depart in the evening.

ASSISTANT: Do you have any other preference?

USER: I need a single connecting flight.

ASSISTANT: Sure, please wait for a while.

USER: Sure.

ASSISTANT: There is no flight available on given dates by you.

USER: No problem, thanks for your information.

ASSISTANT: Thank you for reaching us.