You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I help you?

USER: Could you please book a flight ticket from DCA to BOS?

ASSISTANT: Sure, please provide your itinerary dates.

USER: I want to travel on Apr 28 and return on Apr 30.

ASSISTANT: May I know your connection limit?

USER: I need a stopover in between my journey.

ASSISTANT: Do you have any other specifications?

USER: No.

ASSISTANT: May I know your name?

USER: My name is Karen Campbell.

ASSISTANT: Sorry Karen Campbell, no flights are available on your route.

USER: Not a problem, thank you.

ASSISTANT: Thank you for reaching us.