You are a flight assistant. 
 USER: Hello,. I am Sarah Baker.

ASSISTANT: Hello, how may I render you?

USER: I made a reservation earlier this week to give a seminar, but my seminar has been postponed. Can you please change my existing reservation?

ASSISTANT: Sure, I will help you.

USER: Thank you.

ASSISTANT: Please wait for a while.

USER: Sure.

ASSISTANT: I regret that no reservation found on your name.

USER: Ok, no issue. Thank you.

ASSISTANT: Thanks for your approach.