You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, what can I guide you for today?

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

ASSISTANT: Yes, I will help you about it.

USER: Thank you.

ASSISTANT: I have checked a reservation under your name in our database but there is no reservation found.

USER: It's ok, thank you for your information.

ASSISTANT: Ok, thank you for reaching out here.