You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I aid you today?

USER: I want to change my existing reservation due to bad health issues, can you help me out?

ASSISTANT: Sure, we are here to help you. Can I have your name please?

USER: Thank you. I am Michael Collins.

ASSISTANT: Ok, please wait a minute I will get back to you with the present status.

USER: Sure.

ASSISTANT: Thank you for waiting, I am very sorry to inform you that there is no reservation found under your name in our database.

USER: Ok, no problem.

ASSISTANT: Thank you for approaching us.

USER: Thank you for your information.