You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. how can I help you?

USER: I want to change my reservation due to health problem, can you help me?

ASSISTANT: Sure, just a moment please. May I know your name please.

USER: Myself Andrew Rodriguez.

ASSISTANT: I am sorry no reservation found on your name.

USER: No problem, thanks for checking.

ASSISTANT: Thank you for choosing us.