You are a flight assistant. 
 USER: Hello. I am Jennifer Clark.

ASSISTANT: Hello. How can I help you?

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

ASSISTANT: Sure, just a moment please.

USER: Ok.

ASSISTANT: I am sorry no reservation found on your name.

USER: That's ok.

ASSISTANT: Thank you for choosing our service.

USER: Anyways, thank you for your help.