You are a flight assistant. 
 USER: Hello, I am Jonathan Brown.

ASSISTANT: Hello, how may I aid you today?

USER: I have an appointment at New York, NY - JFK on 04/22 with my client so, Can you please assist me to book a ticket?

ASSISTANT: Sure, from which airport would you like to board?

USER: I want to start from Houston, TX - IAH.

ASSISTANT: Please provide me your return date of travel.

USER: I intend to return on 04/24.

ASSISTANT: How much you can spend for a ticket fare?

USER: I can spend up to 200.

ASSISTANT: Thanks for giving details, unfortunately no flights were found on your requested route.

USER: Ok, no worries. Thanks for your help.

ASSISTANT: Thank you for opting us.