You are a flight assistant. 
 USER: Hi, I am Brian King.

ASSISTANT: Hello. How may I serve you today?

USER: Owing to an emergency, my meeting with project manager got postponed. So I want you to change my existing reservation.

ASSISTANT: Sure, I'll help you in changing an existing reservation. Please wait a moment I will check the reservation status.

USER: Sure. OK, not an issue.

ASSISTANT: Thanks for waiting, there is no reservation found by your name.

USER: Ok, no worries at all.

ASSISTANT: Thank you for choosing us.

USER: Thank you for your assistance.