You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I help you?

USER: I would like to book a ticket from DCA to MSP. Could you book a ticket?

ASSISTANT: Sure, I am here to help you. Can I have your travelling dates?

USER: Departure date is Jan, 19 and return by Jan, 21.

ASSISTANT: Do you prefer any break in between journey?

USER: I would prefer connecting flight.

ASSISTANT: Are there any other specifications for you?

USER: I prefer business class.

ASSISTANT: May I know your good name?

USER: My name is David Perez.

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

USER: Thank you.

ASSISTANT: Thank you for choosing us.