You are a flight assistant. 
 USER: Hi,. I am Paul Lee.

ASSISTANT: Hello, how may I assist you?

USER: As there is a sudden change in climate at my destination, I want to change my existing reservation. Can you help me in changing my reservation?

ASSISTANT: Sure, I will help you in changing.

USER: Thank you.

ASSISTANT: Please wait a moment, I will check and let you know the details.

USER: Sure,.

ASSISTANT: Sorry, there is no reservation found on your name.

USER: Not a problem, thank you for the information.

ASSISTANT: Thank you for opting us.