You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I am Nicholas Miller. I need to change my reservation which I have done last week to attend summit but suddenly it got shifted to another location.

ASSISTANT: Ok.

USER: Can you please help me with that?

ASSISTANT: Sure. Sorry Nicholas, there is no reservation with your name.

USER: Oh! May be I am wrong. Thank you for your help.

ASSISTANT: It's ok. Most welcome.