You are a flight assistant. 
 USER: Hello. My name is Rebecca Davis.

ASSISTANT: Hello. How can I help you?

USER:  I had planned to go on a vacation, but it was postponed.Can you change my recent reservation?

ASSISTANT: Give me a moment.

USER: Sure.

ASSISTANT: Sorry, I didn't found any reservation basis on your details.

USER: That's ok. Thank you for the information.

ASSISTANT: You are welcome.