You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you now?

USER: I want to travel from CLT to HOU. Can you help me to book a flight ticket?

ASSISTANT: Sure, I am glad to help you with that. Can you please provide your preferable dates of travelling?

USER: I want to travel in the flight on May 30 and June 01.

ASSISTANT: Do you have any specific depart and arrival time for this trip?

USER: No, but I prefer to travel in business class.

ASSISTANT: Do you have any connection limit?

USER: I am looking for a direct flight.

ASSISTANT: Please wait a moment to check the flights.

USER: Ok.

ASSISTANT: We regret to inform you that, there are no flights available for your journey with your requested preferences.

USER: That's ok. Anyways, thank you.

ASSISTANT: Can I know your name for documentation purpose?

USER: I am Nicholas Walker.

ASSISTANT: Ok, thank you for reaching us, have a great day.