You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I oblige you today?

USER: I am Gregory Miller. I have an earlier reservation to sign a new contract for new project, due to some problems it got postponed.

ASSISTANT: Ok.

USER: Could you please help me in changing the reservation?

ASSISTANT: Sure, please wait a moment.

USER: Ok.

ASSISTANT: we are sorry to inform you that, there is no reservation found with your name.

USER: No problem, thank you for your information.

ASSISTANT: Thank you for opting us.