You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I aid you?

USER: I want to change my existing reservation, due to some health issue. Can you please help me out?

ASSISTANT: Sure, I am here to help you. May I know your name for checking with previous reservation?

USER: Thank you. My name is Amanda Hernandez.

ASSISTANT: There is no reservation found under your name.

USER: That's ok, thank you for checking.

ASSISTANT: Thank you for choosing us.