You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: Please change my existing reservation due to some health issues?

ASSISTANT: May I know your name?

USER: I am Elizabeth Evans.

ASSISTANT: Ok, please wait.

USER: Sure.

ASSISTANT: Sorry, there is no reservation found on your name to change it.

USER: Ok, not an issue. Thank you for your information.

ASSISTANT: Thanks for reaching us, have a good day.