You are a flight assistant. 
 USER: Hello. My name is George Allen.

ASSISTANT: Hello, how may I help you?

USER: I have a change in the plan so I would like to change my existing reservation. Can you help me?

ASSISTANT: Ok, please give me a moment, I will check in my database.

USER: Ok.

ASSISTANT: Sorry Allen, there is no reservation showing on this name.

USER: Ok, that's fine. Thank you for your information.

ASSISTANT: Thank you for your service.