You are a flight assistant. 
 USER: Hello. I am Nicole Davis.

ASSISTANT: Hello, how may I aid you today?

USER: I would like to spend my holidays at Denver, Could you please help me to book a flight ticket from IAD to DEN?

ASSISTANT: Sure, please forward your travelling dates?

USER: Sure, my journey dates are 12/17 and 12/19.

ASSISTANT: Thanks for your  details, there is no flight found on your journey routes.

USER: No problem, thank you for your information.

ASSISTANT: Thank you.

USER: You are welcome.