You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you today?

USER: I want to change my recent reservation as my interview got postponed, help me in changing my reservation with the name Joseph Moore.

ASSISTANT: Ok, please wait a minute.

USER: Sure.

ASSISTANT: Sorry, there is no reservation found on your name.

USER: No problem, thank you.

ASSISTANT: Thank you for reaching us.