You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello,. How can aid you today?

USER: My name is Anna Davis. I want to change my existing reservation due to international  meeting got postponed.

ASSISTANT: Ok. wait for a while, I will check and revert you back.

USER: Ok.

ASSISTANT: Thanks for waiting. There is no reservation found with your name.

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

ASSISTANT: Thank you for availing us.