You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello,. How can I help you today?

USER: I am Sharon Edwards. My son is giving a presentation on international meeting, but due to some sudden changes, I want to change my existing reservation. Could you help me in changing my existing reservation.

ASSISTANT: Ok. We are glad to help you in changing in your reservation. Please, wait for a moment.

USER: Ok.

ASSISTANT: Thanks for your time. There is no reservation exist on your name in our list of reservation.

USER: Ok, no worries.

ASSISTANT: Thank you for opting us.

USER: Thanks for your service.