You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: Thomas Baker here.

ASSISTANT: How can I aid you?

USER: Can you book a flight ticket for my airport codes that is from DEN to HOU?

ASSISTANT: Sure, I am happy to help you. When are you planning to make your journey?

USER: The travel dates are from 23 Oct to 25 Oct.

ASSISTANT: May I know your specific depart and arrival timings?

USER: The return time would be in the afternoon.

ASSISTANT: Do you prefer any lay by in between journey?

USER: I need a single connection flight.

ASSISTANT: Is there any airline specification for you?

USER: No.

ASSISTANT: Please let me know your class preference.

USER: That does not matter.

ASSISTANT: Thanks for providing details, we regret to inform you that there are no flight services are available on this route with your preferences.

USER: That is not a problem. Thank you.

ASSISTANT: Thank you for choosing us.