You are a flight assistant. 
 USER: Hello. I am David Thompson.

ASSISTANT: Hello, How may I assist you?

USER: Due to sudden changes in whether, I want to cancel my recent reservation?

ASSISTANT: Ok.

USER: Can you please cancel my reservation?

ASSISTANT: Sure, I am glad to help you. Please wait for a while, I will check the previous reservation with your name and let you know.

USER: Ok.

ASSISTANT: Thanks for your patience. We do not found previous reservation with your name.

USER: It's ok. Thank you.

ASSISTANT: Thank you for approaching us.