You are a flight assistant. 
 USER: Hello. I am Nancy Green.

ASSISTANT: Hello, how may I guide you at this moment?

USER: Can you please help me in changing my reservation as my meeting venue got changed to another place?

ASSISTANT: Sure, I am here to assist you.

USER: Thank you.

ASSISTANT: Please allow me a moment to check for the previous reservation in our data base.

USER: Ok.

ASSISTANT: We are sorry to say that, there is no active reservation found on your name.

USER: Ok, no problem. Thank you.

ASSISTANT: Thanks for contacting with us.