You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I support you?

USER: I want to change my existing reservation, due to some health issue. Can you please help me out?

ASSISTANT: Sure, may I know your name please?

USER: My name is Emma Collins.

ASSISTANT: Please give me a moment.

USER: Ok, take your time.

ASSISTANT: We are sorry to inform you that there is no reservation found with your given name.

USER: That's ok, thank you for checking.

ASSISTANT: Thank you.