You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you today?

USER: Brian Clark here, Because of heavy rainfall in JFK I want to change my existing reservation. Please check is there any existing reservation on my name.

ASSISTANT: Give me a moment, let me check your details.

USER: Sure.

ASSISTANT: Sorry, I didn't found any reservation basis on your details.

USER: That's ok, thanks for your information.

ASSISTANT: Thank you for contacting us.