You are a flight assistant. 
 USER: Hi, I am Robert Nelson.

ASSISTANT: Hello, how can I help you today?

USER: Owing to an emergency, my business conference got postponed. So I have a request to you to change my existing reservation?

ASSISTANT: Sure, please wait a while.

USER: Sure.

ASSISTANT: Sorry to say that, no reservation was found on your name.

USER: Ok, no worries at all.

ASSISTANT: Thank you for opting us.

USER: Thanks for your kind service.