You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you?

USER: I want to change my existing reservation due to bade health issues, can you help me with that?

ASSISTANT: May I know your name please?

USER: I am Katherine Lewis.

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

USER: Ok, no issues.

ASSISTANT: Thank you for reaching us.

USER: Thank you for your information.