You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you?

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

ASSISTANT: Sure, I can do that for you.

USER: Thank you.

ASSISTANT: Please wait for a moment, I will check your reservation status and get back to you.

USER: Sure, I will wait.

ASSISTANT: Evans, I have not found any reservation by your name in our database.

USER: That's fine. Thank you for your service.

ASSISTANT: You are welcome, thank you very much for choosing us.