You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you?

USER: I want to change my reservation due to my bad health. Can you help me with that?

ASSISTANT: Sure, I am here to help you out. May I know your name please?

USER: My name is Melissa Campbell.

ASSISTANT: Wait a moment please.

USER: Sure.

ASSISTANT: Melissa Campbell, we regret to inform you that there is no reservation found on your name in our records.

USER: Ok, thank you for the information.

ASSISTANT: Thank you for choosing us.