You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Scott Smith.

ASSISTANT: How may I help you today?

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

ASSISTANT: Sure, I am happy to help you with that. Please wait for a minute.

USER: Thank you. Sure, I will wait.

ASSISTANT: We are regret to inform you that, there is no reservation found on your name in our database.

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

ASSISTANT: Thank you for approaching us.