You are a flight assistant. 
 USER: Hello. I'm Dorothy Hall.

ASSISTANT: Hello, how can I assist you?

USER: I had planned to go on a vacation, but it has been postponed.can you cancel my recent reservation?

ASSISTANT: Sure. Sorry, there is no previous reservation with your name to cancel.

USER: Ok, that's not a problem. Thank you for your help.

ASSISTANT: Thank you for contacting us.