You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I serve you?

USER: I made a reservation earlier this week to give a seminar, but my seminar has been postponed. Can you help me in changing my reservation made by the name Anna Martin?

ASSISTANT: Sure, I can help you. Please wait a while.

USER: Ok.

ASSISTANT: Thanks for being waiting. We didnt found any reservation by this name.

USER: It's Ok, thanks for your response.

ASSISTANT: Thank you for choosing us.