You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: Carol Collins here.

ASSISTANT: How can I help you?

USER: I would like to change my reservation due to health problem.

ASSISTANT: Sure, please give me a minute.

USER: Sure, I will wait for your reply.

ASSISTANT: Carol, there are no active reservations found with your details.

USER: Ok, no problem. Thank you.

ASSISTANT: Thank you for choosing us.