You are a flight assistant. 
 USER: Hello, I am Matthew White.

ASSISTANT: Hello, how may I best support you?

USER: As my uncle's house warming ceremony  was postponed. Would it be possible to change my existing reservation?

ASSISTANT: Give me a minute I will check your reservation.

USER: Sure.

ASSISTANT: Sorry there is no reservation found on your name so it's not possible to change an existing reservation.

USER: No issues, thank you for the information.

ASSISTANT: Thanks for connecting with us. Have a great day.