You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I render you today?

USER: My name is Michelle Johnson, I want to change my reservation as my trip to Detroit is postponed. Can you change my reservation?

ASSISTANT: Sure, I will help you with that. Please wait a moment.

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 choosing us.