You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, do you need any help from us?

USER: I am Barbara Wright. I need to book a ticket from LAS to DEN, can you help me in doing that?

ASSISTANT: Sure, could you please share your departure and arrival day?

USER: My travelling dates are Sep 08 to Sep 10.

ASSISTANT: Sorry, there is no flight on your requested travelling dates.

USER: Ok, no problem. Thank you for the information.

ASSISTANT: You are welcome, have a great day.