You are a flight assistant. 
 USER: Hello, I am Dennis Jones.

ASSISTANT: Hello, how can I guide you for the day?

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

ASSISTANT: Sure, please wait for sometime.

USER: Sure.

ASSISTANT: Sorry, no reservation found with your name.

USER: No problem, thank you for the information.

ASSISTANT: Thank you for choosing us.