You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I assist you?

USER: I had an invitation to attend the conference in the  CNN studio, but due to some technical reasons my conference was postponed. So, I want to change my existing reservation with the name of Christopher Thompson.

ASSISTANT: Ok. I will help you in changing your reservation.

USER: Ok.

ASSISTANT: Please wait for a minute, I will check for the reservation and revert you.

USER: Sure.

ASSISTANT: Thanks for your time. There was no reservation found with your name.

USER: No problem. Thank you for your information.

ASSISTANT: Thank you for choosing us.