You are a flight assistant. 
 USER: Hello. I'm Thomas Lee.

ASSISTANT: Hello Lee. How may I help you today?

USER: My business meeting has been postponed. So, I would like to change my existing reservation which is under my name. Can you please help me with that?

ASSISTANT: Sure Thomas, please wait a minute.

USER: Sure.

ASSISTANT: Thomas, there are no active reservation found with your details.

USER: Ok, no problem.

ASSISTANT: Thank you for reaching us.

USER: Thank you for checking.