You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: Can you help me to book a flight ticket from ATL to DCA?

ASSISTANT: Sure, I am happy to help you. Please let me know your travelling dates.

USER: Apr, 21 and Apr, 23 are my trip dates.

ASSISTANT: Do you prefer any stopover in between journey?

USER: I need direct flight.

ASSISTANT: Are there any other specifications for you?

USER: I need to return at afternoon time with normal cost airlines only.

ASSISTANT: Can I have your good name?

USER: Sarah Jackson here.

ASSISTANT: Sorry, no flights are available on your journey routes.

USER: Not a problem, thank you for the information.

ASSISTANT: Thank you for choosing us.