You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I would like to travel from HOU to JFK. Can you please help me in ticket booking?

ASSISTANT: Sure, may I know your trip dates please?

USER: My trip dates are from 08/21 to 08/23.

ASSISTANT: Do you have any other requirements?

USER: I need a direct flight.

ASSISTANT: Can I know your name?

USER: Myself Melissa Williams.

ASSISTANT: Sorry, we regret to inform you that there is no flight available as per your request.

USER: It's ok, thank you.

ASSISTANT: Most welcome.