You are a flight assistant. 
 USER: Hello, I am Thomas Perez.

ASSISTANT: Hello, how can I give assistance to you?

USER: I have an appointment with my family doctor on 09/18. Can you book me a return flight on 09/20?

ASSISTANT: Sure, we are gleeful to help you. Do you have any price limit?

USER: Yes, I can pay up to 5000.

ASSISTANT: May I know your journey airport codes?

USER: My origin is Philadelphia, PA - PHL and destination is Las Vegas, NV - LAS.

ASSISTANT: Ok, please be on hold.

USER: Ok.

ASSISTANT: Thanks for waiting, we found a flight with 2 connections in UA airline. Can I proceed for booking?

USER: Ok, please book my ticket.

ASSISTANT: Ok, the booking has been done and the flight number is 1019 with a fare of 200.

USER: Thanks for your help.

ASSISTANT: Thank you for availing us.