You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: My son is giving a presentation on international competition, but due to some sudden changes , I want to change my existing reservation. Could you help me?

ASSISTANT: Please provide your name?

USER: My name is Paul Walker.

ASSISTANT: Paul, there is no reservation found on your name.

USER: That's fine, thank you for the information.

ASSISTANT: Welcome.