You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. What service do you need from us?

USER: I want to travel from DFW to IAD. Can you help me to book a flight ticket?

ASSISTANT: Yes, I am happy to help you. Could you please tell me your journey dates?

USER: I want to travel in the flight on Oct 16 and Oct 18.

ASSISTANT: Ok, please mention your airlines preference.

USER: No, but I want to have a connecting flight.

ASSISTANT: May I know your name?

USER: Kevin Smith.

ASSISTANT: Ok, please hold on for a while.

USER: Ok, take your time.

ASSISTANT: Sorry to inform you that, there are no flights found in this way on your planned journey dates.

USER: That's ok. Anyways, thank you.

ASSISTANT: It's my pleasure, thank you for choosing us.