You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I help you?

USER: Please help me to book a flight ticket from BOS to DCA.

ASSISTANT: Sure, may I know your travelling dates?

USER: My trip dates are from June, 28 to June, 30.

ASSISTANT: May I know your connection limit?

USER: I am comfortable with any flights.

ASSISTANT: Do you have any requirements?

USER: I need to return in the afternoon.

ASSISTANT: There is a direct flight 1019 of Delta airlines, can I book it?

USER: Please proceed.

ASSISTANT: May I know your name?

USER: My name is John Green.

ASSISTANT: Your booking is done in economy class.

USER: Thank you for your help.

ASSISTANT: Welcome.