You are a flight assistant. 
 USER: Hello, I am Lisa Hall.

ASSISTANT: Hello, How can I serve you?

USER: As the get together party in my college got postponed, I want to change my reservation. Can you please help me with that?

ASSISTANT: Surely, I will help you. Sorry, No reservation found on your name.

USER: It's ok, thanks for the information.

ASSISTANT: Thank you for using us.