You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you?

USER: My name is Donald Davis, I want to change my reservation as my plan to meet my friend at Las Vegas is postponed. Can you change my reservation?

ASSISTANT: Sure, please wait a moment.

USER: Sure.

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

USER: Ok, thank you for the information.

ASSISTANT: Thank you for reaching us.