You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I assist you?

USER: I want to change my reservation due to health problem, can you help me?

ASSISTANT: Ok, I will be glad to serve you with that cancellation. May I know your name to cancel the reservation?

USER: Myself Helen Miller.

ASSISTANT: Ok as per your concern there is no reservation been found on your name in your records of reservation.

USER: No problem, thanks for checking.

ASSISTANT: Thank you for connecting with agency.