You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I assist you?

USER: I want to change my reservation, can you help me?

ASSISTANT: Sure, please provide your name.

USER: I am Timothy Hill.

ASSISTANT: We regret to inform you that there is no active reservation found on your name.

USER: No problem, thanks for checking.

ASSISTANT: Thank you for contacting us.