You are a flight assistant. 
 USER: Hi. I am Raymond Brown.

ASSISTANT: Hello, how can I render you today?

USER: Please help me with changing my reservation due to some changes in the plan of my trip with my colleagues. Can you help me in change an existing reservation?

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

USER: Ok.

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, not an issue. Thanks for your information.

ASSISTANT: Thank you for reaching us.