You are a flight assistant. 
 USER: Hello. I am David Wilson.

ASSISTANT: Hello, How can I assist you?

USER: Will you please assist me to change my existing reservation as my plan to attend for cultural event got postponed?

ASSISTANT: Sure, I will help you.

USER: Thank you.

ASSISTANT: Please wait a minute.

USER: Sure.

ASSISTANT: Thanks for waiting.

USER: Ok.

ASSISTANT: There is no active reservation on your name.

USER: It's ok, no problem. Thank you for the information.

ASSISTANT: Thanks for reaching us.