You are a flight assistant. 
 USER: Hi. I am Rachel Thompson.

ASSISTANT: Hello, how may I render you today?

USER: Can you please assist me in changing my existing reservation as my meeting got postponed?

ASSISTANT: Sure, please wait for a while.

USER: Ok.

ASSISTANT: Sorry, there is no reservation found on your name.

USER: Ok, no problem. Thank you.

ASSISTANT: Thank you for contacting us.