You are a flight assistant. 
 USER: Hello,. I am Angela Miller.

ASSISTANT: Hello, how can I serve you?

USER: I would like to change my existing reservation due to my Basket ball event has been postponed. Can you please help me with changing my reservation?

ASSISTANT: Sure, I am happy to help you. Please wait for a while.

USER: Ok.

ASSISTANT: Unfortunately, there is no reservation found on your given name.

USER: Ok, no issue.

ASSISTANT: Thanks for choosing us.

USER: Thank you for your service.