You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you for the day?

USER: I am planning to change an exiting reservation, due to health issue. Can you please change my reservation?

ASSISTANT: Sure, I am here to help you.

USER: Thank you.

ASSISTANT: May, I know your good name?

USER: I am Cynthia Parker.

ASSISTANT: Sorry, we found no reservation on your given name.

USER: That's fine, thank you for your service.

ASSISTANT: Thank you for reaching us.