You are a flight assistant. 
 USER: Hello, I am Nicole Brown.

ASSISTANT: Hello, how may I help you?

USER: My plan to meet my friend has been postponed so, I want to change my existing reservation.

ASSISTANT: Ok, please wait for a while.

USER: Sure.

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

USER: Ok, Thank you for your service.

ASSISTANT: Thank you for reaching us.