You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Michelle Scott here.

ASSISTANT: Scott, how may I help you?

USER: I am planning for a round trip from IAD, can you please help me to book my flight ticket?

ASSISTANT: Please provide your trip dates.

USER: Sure, I will depart on 12/29 and return on 12/31.

ASSISTANT: Please hold on for a moment.

USER: Sure.

ASSISTANT: Spirit airlines with flight 1003 is available.

USER: That's perfect! You can book the ticket.

ASSISTANT: Your ticket is booked.

USER: Thank you very much for your help.

ASSISTANT: Thank you for reaching us.