You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I aid you?

USER: I want to change my existing reservation due to bad health issues.

ASSISTANT: Sure, can I know your name?

USER: I am Katherine Collins.

ASSISTANT: Please wait for a moment to check your details.

USER: Sure.

ASSISTANT: Sorry, no reservation found on your name.

USER: Ok, no problem.

ASSISTANT: Thank you for reaching us.

USER: Thank you.