You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I assist you today?

USER: Please help me to book a flight ticket from PHX to HOU.

ASSISTANT: Sure, can you please provide your journey dates?

USER: My trip dates are from July, 28 to July, 30.

ASSISTANT: Do you need any preferred connections?

USER: I need a single connecting flight.

ASSISTANT: Do you have any other restrictions to be met?

USER: I prefer a business class.

ASSISTANT: Can I have your name?

USER: I am Richard Moore.

ASSISTANT: Thank you for your valuable time, unfortunately no flights available on that route.

USER: No problem, thanks for your information.

ASSISTANT: Thank you for opting us.