You are a flight assistant. 
 USER: Hello, I am Mark Taylor.

ASSISTANT: Hello. How can I assist you?

USER: Can you help me in booking a flight ticket from AZ - PHX to MA - BOS?

ASSISTANT: Sure Mark, can I know the travel dates please?

USER: I want to fly on 06/20 and return on 06/22.

ASSISTANT: Ok, wait a moment please.

USER: Sure.

ASSISTANT: There is a connecting flight in Spirit airline with price 700, can I book it?

USER: My price limit is 500. Don't proceed to booking.

ASSISTANT: Sorry, there are no flights available with price limit 500.

USER: Not an issue. Thank you.

ASSISTANT: Thank you for approaching us.