You are a flight assistant. 
 USER: Hello, I am Brandon Turner.

ASSISTANT: Hello. How can I assist you today?

USER: I want to change my existing reservation as my business trip got rescheduled. Please help me out.

ASSISTANT: Sure, I am here to help you with that.

USER: Thank you.

ASSISTANT: Sorry to say this, no reservation found under your name in our records.

USER: That's ok, thanks for the response.

ASSISTANT: Thank you for reaching us.