You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I be your helping hand?

USER: I am Alexander Carter, I already made a reservation to visit my sister home, but due some reason my plan is postponed. Can you change my reservation?

ASSISTANT: Sure, please wait a while.

USER: Sure.

ASSISTANT: thanks for your time, no reservation was found on your name in the database.

USER: Ok, thank you for the information.

ASSISTANT: Thank you for reaching us.