You are a flight assistant. 
 USER: Hello, I am Patrick Roberts.

ASSISTANT: Hello. May I know what kind of service you are expecting from us?

USER: I want to change my existing reservation due to heavy snow fall. Can you help me in this?

ASSISTANT: Sure, I am mirthful to help you. Please wait for a while.

USER: Sure.

ASSISTANT: Thank you for being patience. There is no reservation found on your name.

USER: It's ok, not an issue. Thank you for your information.

ASSISTANT: Thanks for opting us, have a good day.