You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you?

USER: I am Daniel Edwards here. I need to book my ticket from DEN to IAD. Can you please help me with booking my flight ticket?

ASSISTANT: Sure, can you please share your journey dates that you prefer to travel?

USER: I prefer to travel on Dec 21 and return back on Dec 23.

ASSISTANT: Do you have any specifications?

USER: Yes, I need a direct flight in my journey.

ASSISTANT: Ok, please wait for a while.

USER: Sure.

ASSISTANT: Sorry, there were no flights found on your route.

USER: Ok, not an issue. Thank you for your kind information.

ASSISTANT: Thank you for reaching us.