You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I aid you?

USER: due to my ill health, I want to change my existing reservation.

ASSISTANT: Ok, can I know your name?

USER: My name is Virginia Davis.

ASSISTANT: Davis, we did not find any reservation with your name. May be I think on that day, you hadn't done your reservation properly.

USER: Ok, thank you for your information.

ASSISTANT: It's my pleasure.