You are a flight assistant. 
 USER: Hello. I am Katherine Anderson.

ASSISTANT: Hello, How can I support you today?

USER: I have made a reservation earlier to New York, I want to modify my reservation.

ASSISTANT: Sure, I will help you with that. Please hold on for a while.

USER: Sure.

ASSISTANT: Thank you for waiting. I have checked in reservation list to change your ticket, but could not find any reservation with your name.

USER: Ok. Thank you.

ASSISTANT: Thank you for choosing us.