You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I aid you for today?

USER: David Martin here. Could you book my ticket in a direct flight?

ASSISTANT: I am here to help you with that. Can you please provide your planned dates of journey?

USER: My itinerary dates are Dec 19 and Dec 21.

ASSISTANT: Could you please provide your respective airport codes?

USER: My genesis and terminus airport codes are DFW and CLT.

ASSISTANT: I regret to say that David Martin, I am not able to book your flight ticket as no flights are travelling to your region.

USER: No problem, thank you.

ASSISTANT: You are welcome, thank you for reaching us.