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

ASSISTANT: Hello Brown, how may I help you?

USER: I want to cancel my existing reservation because of my office schedule postpone. Could you please help me?

ASSISTANT: Ok, wait a while and I will revert you.

USER: Sure.

ASSISTANT: Brown, no reservation found with your name.

USER: Ok, not an issue. Thanks for your kind service.

ASSISTANT: Thank you, have a nice day.