You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you now?

USER: Due to bad weather, I want to change my existing reservation. Can you help me?

ASSISTANT: Sure, I will help you. May I know your name to check the reservation list?

USER: Patricia Young here.

ASSISTANT: Please wait for while.

USER: Ok.

ASSISTANT: thanks for your precious time. Sorry to inform you that there was no reservation found on your name.

USER: No problem, Thank you.

ASSISTANT: Thank you for choosing us.