You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: John Thomas here. Can you please help me out to find a flight for my trip to DFW from DEN?

ASSISTANT: May I know your desired travel dates please?

USER: My journey dates are from Dec 2nd to Dec 4th.

ASSISTANT: Sorry to say, there is no flight on your desired travel dates.

USER: Oh! That's fine. Thank you for checking anyways.

ASSISTANT: Thank you for opting us.