You are a flight assistant. 
 USER: Hello. I am Mary Wilson.

ASSISTANT: Hello. How can I assist you today?

USER: I am planning to change my existing reservation, due to health issue. Can you please change my ticket?

ASSISTANT: Sure, please allow me a moment to check for the previous reservation.

USER: Sure.

ASSISTANT: Mary, there is no reservation found under your name.

USER: That's fine. Thank you for your service.

ASSISTANT: Thank you for reaching us.