You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, what kind of help do you want?

USER: I want change an existing reservation due to sudden change in my trip.

ASSISTANT: Sure, may I know your name?

USER: Can you help me with that? I am Richard White.

ASSISTANT: Sure, we are here to assist you. Ok, please wait for a moment.

USER: Ok.

ASSISTANT: Sorry to say, we did not find any reservation to change on your name.

USER: Ok ,  Thank you for your response.

ASSISTANT: Thanks for picking our service.