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: I will help you with that please share your name to proceed further?

USER: Sure, I am Anthony White.

ASSISTANT: No reservation found under your name in our database.

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

ASSISTANT: Thank you for choosing us.