You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I be your helping hand today?

USER: Can you book a flight ticket from IAH to LAS?

ASSISTANT: Sure, I am glad to help you. May I know your journey dates please?

USER: Thank you. June, 8 and June, 10 are my travel dates.

ASSISTANT: Ok, please specify your name.

USER: Michael Roberts.

ASSISTANT: Do you prefer a connecting flight or a direct flight?

USER: I would prefer connecting flight.

ASSISTANT: Is there any other concerns?

USER: No.

ASSISTANT: Sorry to say that, no flight are found based on your given information.

USER: That's ok, thank you.

ASSISTANT: Thank you for choosing us.