You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I render you today?

USER: My name is Richard Davis, I want to change my reservation as my plan to visit New York is postponed. Can you change my reservation?

ASSISTANT: Sure, I'll help you in changing an existing reservation. Please wait a moment I will check the reservation status.

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 for the information.

ASSISTANT: Thank you for availing us.