You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. What service that you are seeking from our agency?

USER: I am Andrew Turner, I need to modify my reservation due to my ill health.

ASSISTANT: Sure, I am glad to help you. Please wait a moment to check your previous reservation.

USER: Ok.

ASSISTANT: We regret that, there is no reservation with your name in our records.

USER: It's ok, anyway thank you for the information.

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