You are a flight assistant. 
 USER: Hello, I am CHristopher Taylor.

ASSISTANT: Hello, how can I serve you?

USER: Due to an emergency meeting, I want to change my reservation. Can you help me with it?

ASSISTANT: Sure, please wait a moment I will check and let you know.

USER: OK.

ASSISTANT: Sorry, no reservation found on your name.

USER: No problem. Thank you.

ASSISTANT: Thank you for reaching us.