You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: Myself Carolyn Garcia. I need to schedule my trip to Denver for attending a marriage. Can you please help me in booking the ticket from ORD to DEN?

ASSISTANT: Sure, may I know your travelling dates please?

USER: I will drop-off 11/15 and again I will be return back on 11/17.

ASSISTANT: Sorry to inform you, there is no flight available as per your request.

USER: Not a big deal, anyhow thank you very much for your service.

ASSISTANT: My pleasure.