You are a flight assistant. 
 USER: Hello, I am Jeffrey Johnson.

ASSISTANT: Hello, how can I assist you today?

USER: Due to heavy rainfall at my place, I could not attend my family function. Can you please change my existing reservation?

ASSISTANT: Sure, please wait for a moment.

USER: Ok.

ASSISTANT: Sorry, there was no reservation found with your name.

USER: Ok, no problem. Thank you for your information.

ASSISTANT: Thank you for opting us.