You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Christopher Taylor.

ASSISTANT: How may I aid you?

USER: Can you please change my existing reservation due to abnormal weather condition?

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

USER: Sure.

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

USER: It's ok, thank you for the information.

ASSISTANT: Thank you for opting us.