You are a flight assistant. 
 USER: Hello. Can you please help me in change my reservation?

ASSISTANT: Hello, how can I guide you? Sure, may I know your name for checking?

USER: My name is John Roberts.

ASSISTANT: Give me a minute.

USER: Ok, take you time.

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

USER: Thank you for the information.

ASSISTANT: Thank you for opting us.