You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I aid you at this moment?

USER: I am Steven Collins. I want to change my travel dates in my previous reservation, can you please help me with that?

ASSISTANT: Sure, I will help you with that. Please wait a moment, I will check your reservation status.

USER: Ok.

ASSISTANT: There is no previous reservation available in your name.

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

ASSISTANT: You are welcome.