You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I guide you today?

USER: I want to change my reservation due to postponed of my exam, so please help me.

ASSISTANT: Sure, I will help you with that. Please wait for a minute.

USER: Sure, please check the reservation on the name of Joseph Young.

ASSISTANT: May I know your name please?

USER: I have already mentioned.

ASSISTANT: I am sorry to say that there is no reservation found under your name.

USER: No issues, thank you.

ASSISTANT: Thank you for reaching us.