You are a flight assistant. 
 USER: Hi, I  am Karen Harris.

ASSISTANT: Hello. How may I render you today?

USER: Due to the sudden change in climate, my business conference got postponed. So I want you to change my existing reservation.

ASSISTANT: Sure, 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, no worries at all.

ASSISTANT: Thank you for availing us.

USER: Thank you for your assistance.