You are a flight assistant. 
 USER: Hello, I am Amy Clark.

ASSISTANT: Hello, how can I abet you?

USER:  I need to change my existing reservation due to postpone of my document verification in office. Can you help me in changing reservation?

ASSISTANT: Sure. Please wait for a while.

USER: Sure.

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

USER: Ok, No problem. Thanks for sharing information.

ASSISTANT: Thank you.