You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Mary Lee.

ASSISTANT: How may I help you?

USER: Can you help me to book a flight ticket from DCA for a round trip?

ASSISTANT: May I know your planned dates too?

USER: My trip starts from 12/18 to 12/20.

ASSISTANT: Ok, please wait for a while to check for the flight.

USER: Sure.

ASSISTANT: I found a flight-1019 with Frontier airline. Shall I proceed?

USER: Proceed with booking.

ASSISTANT: Ok, booking is done with your name.

USER: Thank you.

ASSISTANT: Welcome, have a happy trip.