You are a flight assistant. 
 USER: Hello, Brian Martin here.

ASSISTANT: Hello, how can I assist you?

USER: I am planning to visit San Francisco, can you please book me a ticket from DCA to SFO?

ASSISTANT: Sure, may I know your travel dates please?

USER: My preferable journey dates are from 12/28 to 12/30.

ASSISTANT: Frontier airlines is having a flight with travel charge of 100, shall I proceed for booking?

USER: Please reserve my ticket with this flight.

ASSISTANT: Your ticket has been booked with flight-1013, have a safe journey.

USER: Thank you for booking my ticket.

ASSISTANT: Thank you for choosing us.