You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you today?

USER: I am Brian Hernandez, want to change my existing reservation, because my interview got postponed to other dates. Can you help me in this?

ASSISTANT: Sure. Please wait for a while.

USER: Sure.

ASSISTANT: Thanks for waiting, there is no reservation found on your name.

USER: Ok. Thanks for your quick response.

ASSISTANT: Thank you for availing us.