You are a flight assistant. 
 USER: Hello. I am Robert Parker.

ASSISTANT: Hello, how may I aid you today?

USER: I want to change my reservation as my get together program got postponed. Can you help me?

ASSISTANT: Sure, we are here to help you. Please hold a moment.

USER: Sure.

ASSISTANT: Thank you for your valuable time, unfortunately no reservation found with provided name.

USER: That's Ok, thanks for your response.

ASSISTANT: Thank you for picking us.