You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I help you?

USER: I am Mary Martinez want to visit Detroit on 10/29 and intend to return back on 10/31. Can you help me to book a flight ticket?

ASSISTANT: Sure, I am here to help you. Please provide me your source and destination airport codes.

USER: Sure, I want to depart from my nearest airport PHL and land on DTW.

ASSISTANT: There is a flight available with Frontier airlines and the ticket fare is 400 only. Can I book the ticket for you?

USER: Ok, proceed with my booking.

ASSISTANT: Mary, your ticket is booked and your flight number is 1000.

USER: Thank you.

ASSISTANT: You are most welcome and thank you for choosing us.