You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I assist you?

USER: David Lewis here. I would like to book a ticket from DCA to ATL, can you please help me with that?

ASSISTANT: Sure, let me know your travelling dates.

USER: The travel dates are from May 23 to May 25.

ASSISTANT: Please share your connection limit.

USER: I need a halt.

ASSISTANT: Do you have any requirements?

USER: I want to return in evening time.

ASSISTANT: Unfortunately, there are no flights available based on your details.

USER: That's ok, thank you for your help.

ASSISTANT: Thank you for choosing us.