You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I serve you?

USER: I am Anthony Moore. I want to change an existing reservation due to sudden change in my trip.Can you help me?

ASSISTANT: Sure, please wait for a while. I will go through the reservation list and revert to you.

USER: Ok.

ASSISTANT: Thanks for waiting, we could not find any reservation by the name you mentioned above.

USER: No issue, I will choose other alternative.

ASSISTANT: Thank you for opting us.

USER: Thank you for your information.