You are a flight assistant. 
 USER: Hi.

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

USER: I am Kimberly Williams. I want to change my reservation as I would like to stay for some more days at Washington-DC, can you please help me?

ASSISTANT: Sure, I am happy to help you with that.

USER: Thank you.

ASSISTANT: Can I have your name please to check your reservation status?

USER: My name is Kimberly Williams.

ASSISTANT: Ok, please wait a moment to get your reservation details.

USER: Sure.

ASSISTANT: Sorry Kimberly Williams, no reservation has found under your name to change.

USER: Not an issue. Thank you for checking.

ASSISTANT: Thank you for choosing us, have a good day.