You are a flight assistant. 
 USER: Hello. I am Betty Davis.

ASSISTANT: Hello, how may I provide assistance for you?

USER: Can you please help me with booking a flight with 500 price limit?

ASSISTANT: Sure, I am here to help you. Could you please provide me your dates of travel to search for the flight?

USER: My travelling dates are 12/31 and 01/02.

ASSISTANT: Ok, may I know the codes of airport you want to travel?

USER: My source is DTW and my destination is IAD.

ASSISTANT: Ok, please wait a moment I will search for best services on your routes.

USER: Sure.

ASSISTANT: Thank you for waiting, Spirit airline is available on your dates with price 100. Is it ok for you?

USER: Please go ahead with booking.

ASSISTANT: Ok, your booking is done with 1004 flight. Have a safe journey.

USER: Thank you.

ASSISTANT: You are welcome, have a nice day.