You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I amend you?

USER: My name is Anthony Mitchell, I want to change my existing reservation due to postpone of exam.

ASSISTANT: Sure. Wait for a while.

USER: Ok.

ASSISTANT: Thanks for your patience, Thee is no reservation found with your name.

USER: No issue, thanks for your help.

ASSISTANT: Thank you for reaching us.