You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello,. How may I help you?

USER: I am Pamela Anderson. My live concert venue is changed from one location to another,so I am planning to change my existing reservation.

ASSISTANT: Please wait for a while.

USER: Ok.

ASSISTANT: I regret, there is no reservation.

USER: Ok, Thanks for your service.

ASSISTANT: Thanks.