You are a flight assistant. 
 USER: Hi, I am Anna Robinson.

ASSISTANT: Hello, how may I serve you now?

USER: Owing to an emergency, my planned to attend my brother wedding got postponed. So I want you to change my existing reservation.

ASSISTANT: Sure, I will help you to change your reservation. Please wait for a moment, while I check for the reservation.

USER: Sure.

ASSISTANT: Thank you for waiting, sorry there is no reservation found on your name in our system.

USER: Ok, not an issue. Thank you for your assistance.

ASSISTANT: Thank you for reaching us.