You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you today?

USER: Can you please change my reservation, due to health issues?

ASSISTANT: Sure, may I know your name for the change reservation process?

USER: Sure. my name is Michael Evans.

ASSISTANT: Unfortunately, no flights available on your requirements.

USER: Ok, no issue.

ASSISTANT: Welcome, thank you for reaching us.

USER: Thank you.