You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I help you?

USER: My name is Larry Baker, please check for the best flight from PHX to IAD.

ASSISTANT: Sure, on which dates are you planning your journey?

USER: Yes, I have to depart on 01/21 and return on 01/23.

ASSISTANT: Larry, Spirit airline is providing service on that route with flight-1004 and the travel charge is 100. Shall I book the ticket?

USER: Sure, please book my ticket.

ASSISTANT: Your ticket has been booked successfully, have a safe flight.

USER: Thank you very much.

ASSISTANT: Thank you so much for choosing us.