You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Brenda Robinson.

ASSISTANT: Do you want me to help you with anything?

USER: Yes. I want to change my reservation to next month. Can you help me out?

ASSISTANT: Sure, I will help you that. Give me a minute.

USER: Ok.

ASSISTANT: I am sorry to say that there is no reservation found.

USER: That's fine. Thank you.

ASSISTANT: Thank you for contacting us.