You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: I want to change my reservation due to sudden change in my trip. Can you assist me?

ASSISTANT: Sure, I am here to assist you.

USER: Thank you.

ASSISTANT: May I know your name please?

USER: Brian Mitchell.

ASSISTANT: Ok, please wait a minute.

USER: Sure.

ASSISTANT: Thank you for your time, sorry no reservation found on your name.

USER: No problem, thank you for searching.

ASSISTANT: Thank you for reaching us, have a nice day.