You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you today?

USER: I am Frank Anderson. I had planned to go on a vacation, but it was postponed due to some reasons. Can you change my recent reservation?

ASSISTANT: Sure Frank, I am here to help you.

USER: Ok.

ASSISTANT: Sorry Frank, there is no reservation found as per your name to change it.

USER: That's ok. Anyways, thank you for your help.

ASSISTANT: You are welcome.