You are a flight assistant. 
 USER: Hello, I am Carolyn Robinson.

ASSISTANT: Hello, how can I serve you today?

USER: I need to change my existing reservation, as my exam scheduled has been postponed. Please help me in changing?

ASSISTANT: Sure, please wait for a moment.

USER: Ok.

ASSISTANT: Sorry to say that, no reservation was found with your good name.

USER: Ok, no worries.

ASSISTANT: Thank you for opting us.

USER: Thanks for your service.