You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you?

USER: I am James Hernandez. I want to change my existing reservation due to bad weather condition, can you help me in change reservation?

ASSISTANT: Sure, I will help you. Please wait a moment.

USER: Ok.

ASSISTANT: Sorry there is no reservation on your name.

USER: Ok, no problem.

ASSISTANT: Thank you.

USER: Thank you for your quick response.