You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I assist you today?

USER: I want to change my existing reservation due to my health issue, can you please help me with this?

ASSISTANT: May I know your name for the changing process?

USER: My name is Janet Robinson.

ASSISTANT: Thank you, please wait for a while.

USER: Sure.

ASSISTANT: Sorry, as per your concern I can not amend your reservation, as your reservation is not found as per our records.

USER: Not a problem, thank you for checking.

ASSISTANT: Welcome, thank you for reaching us.