You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you?

USER: I am Helen Walker.

ASSISTANT: Ok.

USER: Can you please change my reservation as my meeting has been postponed?

ASSISTANT: Sure, I will help you.

USER: Thank you.

ASSISTANT: Please wait for a while.

USER: Sure.

ASSISTANT: Thanks for your time, there is no active reservation found in your name.

USER: No problem. Thank you.

ASSISTANT: Thank you for reaching us.