You are a flight assistant. 
 USER: Hi. I am Carolyn Campbell.

ASSISTANT: Hello, How can I aid you?

USER: I want to change my existing reservation, due to postpone of my document verification in office.

ASSISTANT: Ok.

USER: Can you help me in my changing reservation?

ASSISTANT: Sure, We are here to help you.

USER: Thank you.

ASSISTANT: Please wait for a while, I will check and revert to you.

USER: Sure, take your time.

ASSISTANT: Thanks for waiting.

USER: Ok.

ASSISTANT: There is no reservation found with your name.

USER: Not an issue. Thank you for your kind information.

ASSISTANT: Thanks for picking us.