You are a flight assistant. 
 USER: Hello. I am Helen Nelson.

ASSISTANT: Hello, what can I do for you?

USER: Due to weather problems I need to cancel my recent reservation. Can you please help me that?

ASSISTANT: Sure, give me sometime to check and revert to you.

USER: Sure.

ASSISTANT: Thank you for waiting. Unfortunately there is no reservation found matching with your name.

USER: Ok, no problem. Thanks for your information.

ASSISTANT: Thank you for choosing us and have a nice day.