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, may I know your name please?

USER: Scott Campbell.

ASSISTANT: I am sorry no reservation found on your name.

USER: No problem, thank you for searching.

ASSISTANT: Thank you for choosing us.