You are a flight assistant. 
 USER: Hi.

ASSISTANT:  Hello, how may I render you today?

USER: Due to some entrepreneurship meeting, I am going to change my existing reservation. Can you please help me in changing the reservation?

ASSISTANT: Sure, may I know your good name?

USER: I am Frank Allen.

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

USER: Sorry, there is no reservation by your name.

ASSISTANT:  Thank you for choosing us.