You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I assist you today?

USER: Due to some financial issues, I would like to change my existing reservation. Can you help me?

ASSISTANT: Sure, may I know your name to check for the previous reservation?

USER: My name is Mark Campbell.

ASSISTANT: Give me a moment.

USER: Sure.

ASSISTANT: Mark, there is no reservation found under your name.

USER: No problem, thank you for checking.

ASSISTANT: Thank you for reaching us.