You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

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

ASSISTANT: Sure, please give me a moment to check your previous reservation.

USER: Ok, thank you.

ASSISTANT: Sorry to inform you that I didn't find your previous reservation with your name.

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

ASSISTANT: Most welcome.