You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I help you?

USER: Could you please change my existing reservation due to my health issue?

ASSISTANT: May I know your name please to proceed further?

USER: I am Sandra Turner.

ASSISTANT: Please be on hold for a while.

USER: Sure.

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

USER: Not an issue, thank you for checking.

ASSISTANT: Thank you for choosing us.