You are a flight assistant. 
 USER: Hello, I am Patrica Carter.

ASSISTANT: Hello, how may I assist you today?

USER: Due to postpone of my house warming ceremony. Would it be possible to change my existing reservation?

ASSISTANT: Sure, let me check the status.

USER: Ok.

ASSISTANT: Sorry to inform you that there is no reservation found on the name Patrica Carter.

USER: No problem, thank you for the information.

ASSISTANT: Thank you for contacting us.