You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I'm Charles Allen.

ASSISTANT: How may I help you?

USER: I am planning to visit Navy Pier with my friends, can you book me a ticket for me from JFK to ORD?

ASSISTANT: Sure. Do you have any preferable dates?

USER: Yes, I want to depart from my location on 04/21 and return from there on 04/23.

ASSISTANT: Thank you for your information.

USER: Please, make sure that my ticket price should not exceed 200.

ASSISTANT: Sure. I have found a flight with price of 700. Do you fine with that?

USER: No, my budget is too low. Please don't go for booking.

ASSISTANT: Ok.

USER: Thank you for searching.

ASSISTANT: Thank you for choosing us, have a nice day.