You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I aid you?

USER: Myself Barbara Parker from Washington. I want to change my travel dates in my previous reservation. Can you please help me with that?

ASSISTANT: Sure, I am glad to help you in modifying your reservation.

USER: Thank you for your positive response.

ASSISTANT: Please allow me a moment to check for your previous reservation status.

USER: Ok.

ASSISTANT: Thank you for waiting.

USER: It's ok.

ASSISTANT: Sorry to say Parker, there is no active reservation have been found under your name in our database to amend it.

USER: Oh! It's ok no problem. Thank you for your information.

ASSISTANT: Thank you for reaching us.