You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I help you?

USER: Me and my family members want to travel in flight, could you book me any airline from DEN to LAS?

ASSISTANT: sure, may I know trip dates?

USER: We planned from 02/28 to 03/01.

ASSISTANT: Give me a moment.

USER: Ok.

ASSISTANT: May I know your name for further proceedings?

USER: My name is Deborah Young, please book me a ticket with price of 500.

ASSISTANT: Sorry Young, there is no flight with your requirements. Do you any other dates to travel?

USER: Sorry, we have no free time to travel in other dates. Thank you for your help.

ASSISTANT: Thank you for choosing us.