You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you today?

USER: I have an important party to attend at my friends house. So, I would like to change my existing reservation.

ASSISTANT: Let me check your details. May I know your name please?

USER: My name is Jeffery Collins.

ASSISTANT: Sorry, I didn't found any reservation basis on your details.

USER: That's ok. Thank you for the information.

ASSISTANT: You are welcome.