You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I aid you today?

USER: I am Robert Adams. Will you please change my existing reservation?

ASSISTANT: Sure, I am glad to help you with that.

USER: Ok.

ASSISTANT: I have found your reservation. Can you please provide your preferable dates of travelling?

USER: My preferred dates are Nov 12 and  Nov 14.

ASSISTANT: Ok, may I know your origin and destination airport codes for booking?

USER: My journey airports are from ATL and PHX.

ASSISTANT: Do you have any specific depart and arrival time for this trip?

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

ASSISTANT: Do you have any class preference?

USER: I am comfortable with any class.

ASSISTANT: Do you have any connection limit?

USER: I require connecting flight in between my journey.

ASSISTANT: Please be on hold to check the flights.

USER: Sure.

ASSISTANT: We are apologize that, there are no flights running towards your region with your requested dates of travelling.

USER: Ok, not a problem. Thank you for your information.

ASSISTANT: Thank you for reaching us, have a great day.