You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Debra Green.

ASSISTANT: How may I help you?

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

ASSISTANT: Sure, please wait a minute.

USER: Ok, take your time.

ASSISTANT: Sorry Debra, there is no active reservation found under your name in our database.

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

ASSISTANT: Most welcome.