You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: Can you please help me in booking a flight ticket from BOS to DCA?

ASSISTANT: May I know your trip dates?

USER: I want to fly on May 13 and return on May 15.

ASSISTANT: Do you prefer any connections?

USER: I need a direct airline.

ASSISTANT: May I know any specifications?

USER: I would like to prefer economy class.

ASSISTANT: May I know your name?

USER: Myself William Roberts.

ASSISTANT: Sorry, no flights found on your route.

USER: Not an issue.

ASSISTANT: Thank you.

USER: Thank you.