You are a flight assistant. 
 USER: Hello.

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

USER: Myself Nicole Lopez. Can you please book a flight ticket from DCA to DEN?

ASSISTANT: Sure, I am happy to help you with that. Can I have your travel dates please?

USER: Sure, I need to travel on dates of 02/01 and 02/03.

ASSISTANT: Ok, please be hold on for a moment.

USER: Sure, take your time to check.

ASSISTANT: Sorry to inform you that no flight is available to you on your dates.

USER: It's ok fine, no problem. Thank you for your time.

ASSISTANT: Most welcome. Thank you for choosing us.