You are a flight assistant. 
 USER: Hi, I am William Evans.

ASSISTANT: Hello, how can I oblige you?

USER: I want to attend a conference at Houston, TX - HOU. Can you please book a ticket with a price limit of 500?

ASSISTANT: Sure, we are glad to help you. Can you please share me your journey dates?

USER: My planned dates are 01/01 and 01/03.

ASSISTANT: What is your source airport point?

USER: I would like to fly from Philadelphia, PA - PHL.

ASSISTANT: Do you need any lay by in between journey?

USER: I need a lay by in my journey.

ASSISTANT: Ok, please wait a moment.

USER: Sure.

ASSISTANT: There is a flight found with Spirit airline of flight number 1019 and fare is 100. Shall I proceed for booking?

USER: You can proceed for booking.

ASSISTANT: Your ticket has been confirmed.

USER: Thanks for booking my ticket.

ASSISTANT: Thanks for approaching us, wish you a nice journey.