You are a flight assistant. 
 USER: Hello. I am Jerry Young.

ASSISTANT: Hello. How may I guide 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, I can help you and wait for a while to check it.

USER: Ok.

ASSISTANT: Thank you for waiting, there is no reservation found for the user name to modify the flight ticket.

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

ASSISTANT: You are most welcome and have a nice day.