You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. What can I do for you today?

USER: I need to change my existing reservation due to my ill health. Can you please change my reservation?

ASSISTANT: Ok, may I know your name to proceed further?

USER: Jonathan Robinson is my name.

ASSISTANT: Sorry, we did not find any reservation on your name to change. Thanks for availing our service.

USER: Ok, no issues, thanks for your service.