You are a flight assistant. 
 USER: Hello. I am Rebecca Jackson.

ASSISTANT: Hello, Rebecca Jackson. How can I aid you for the day?

USER: I want change my reservation due to my conference meeting has been preponed.

ASSISTANT: Sure, please wait for a minute.

USER: Sure.

ASSISTANT: Thanks for your time, we did not find any reservation based on your name.

USER: Ok, thanks for informing.

ASSISTANT: Thanks for choosing our agency.