You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you today?

USER: I want to change my existing reservation. Can you please help me in that?

ASSISTANT: Sure, may I know your name for change in the reservation?

USER: Myself Jeffrey Thompson.

ASSISTANT: Please wait a moment.

USER: Ok.

ASSISTANT: Found your reservations, may I know your new airport codes?

USER: My preferred airport codes are ORD to DTW.

ASSISTANT: Please mention your new travelling dates.

USER: My trip dates are Oct 26 to Oct 28.

ASSISTANT: Do you need any connection limit for this travel.

USER: I need a connecting flight.

ASSISTANT: Is there any other specifications needed?

USER: My depart should be in the morning.

ASSISTANT: Please hold a moment.

USER: Ok.

ASSISTANT: Sorry, there are no flights found on your given dates.

USER: Ok, no problem. Thank you for checking.

ASSISTANT: Thank you for reaching our services.