You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Karen Jackson.

ASSISTANT: How can I assist you at this moment?

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, I will help you in changing your reservation. Please give me a moment to check your reservation status.

USER: Ok, take your own time.

ASSISTANT: Karen Jackson, there is no active reservation found under your name in our database to make the changes.

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

ASSISTANT: Thank you for utilising our service.