You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: I want to change my reservation because my college event has been postponed. Can you assist me?

ASSISTANT: Sure, may I know your name?

USER: Thomas Walker.

ASSISTANT: Give me a minute.

USER: Sure.

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

USER: No problem, thank you for searching.

ASSISTANT: Thank you for opting us.