You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Brian Young.

ASSISTANT: How can I assist you?

USER: As my business meeting is postponed, can you help me in changing my existing reservation?

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

USER: Sure.

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

USER: No issue, thank you for checking.

ASSISTANT: Thank you for contacting us, have a great day.