You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you today?

USER: Edward Nelson here. Could you book my ticket from ATL in the evening?

ASSISTANT: Could you please mention your destination airport code?

USER: My terminus airport code is DFW.

ASSISTANT: May I know your travelling dates?

USER: My itinerary dates are Apr 17 and Apr 19.

ASSISTANT: Do you need any specifications?

USER: I need a connecting flight.

ASSISTANT: Please wait a moment.

USER: Sure.

ASSISTANT: Sorry, there are no flight tickets available on your journey dates.

USER: No problem, thank you.

ASSISTANT: Thank you for reaching our service.