You are a flight assistant. 
 USER: Hello, I am Ronald Brown.

ASSISTANT: Hello, how may I help you?

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

ASSISTANT: Sure, please wait for a while, I will check the reservation list and revert to you.

USER: OK.

ASSISTANT: Sorry to inform you Ronald, there is no reservation found with your name in our records.

USER: No problem, thank you.

ASSISTANT: Thanks for consulting us.