You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, may I know your name?

USER: Can you help me to book a flight on my name, Gregory Smith?

ASSISTANT: Sure, can you provide your preferable dates of journey?

USER: I am planning to travel on 03/19 and 03/21.

ASSISTANT: Can you mention your destination of your journey?

USER: I would like to visit DEN, to meet my family.

ASSISTANT: Please provide me your source city airport.

USER: I want to start my journey from DTW.

ASSISTANT: Hold on I will revert back with the proper information of the flight.

USER: 200 is my price limit. Ok.

ASSISTANT: Our service don't provide any flight with such a price to your preferable destination.

USER: Oh! really sad. That's fine. Thank you for your support.

ASSISTANT: You are welcome.Hope you have a great day ahead.