You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I serve you?

USER: I am David Garcia. I am planning to book a ticket to meet my family at DEN. Can you please help me out to book a ticket?

ASSISTANT: Yes, on what dates that you are preferring to travel?

USER: I would like to travel on 04/02 and return back on 04/04.

ASSISTANT: Please confirm your source region which is nearest to you.

USER: My nearest source airport code is LAX.

ASSISTANT: Let me check for the flight, please be on hold.

USER: Sure, take your own time.

ASSISTANT: I am sorry that there are no flights found on your trip dates to book your flight ticket.

USER: That's fine. Thank you for your service.

ASSISTANT: Have a nice day, thank you for reaching us.