You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you?

USER: Due to my ill health, I want to change my existing reservation. Please help me out.

ASSISTANT: Sure, can I know your good name please?

USER: My name is Barbara Carter.

ASSISTANT: There is no reservation found under your name, Barbara.

USER: Ok, no issue. Thank you for your information.

ASSISTANT: Thank you so much for choosing us.