You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you?

USER: Because of postpone of my examination which is at Denver, can you please help me to change my reservation towards to Austin?

ASSISTANT: Sure, may I know your name to check for the previous reservation?

USER: Ok, my name is Christopher Green.

ASSISTANT: Give me a minute.

USER: Sure, take your time.

ASSISTANT: There is no reservation found under your name.

USER: Ok, no problem. Anyways, thank you for your service.

ASSISTANT: You are welcome.