You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I guide you for today?

USER: I need to travel DEN and IAH, can you reserve flight ticket?

ASSISTANT: Can you please share on what dates you are willing to travel?

USER: My travelling dates are June,08 and June,10.

ASSISTANT: Are you looking for a connecting flight or direct flight?

USER: I prefer direct flight only.

ASSISTANT: Do you have any class preferences?

USER: No other specifications needed.

ASSISTANT: Can you please provide your name to proceed further?

USER: Myself Daniel Johnson.

ASSISTANT: Sorry, there are no flights available at your request.

USER: Oh! Sad to hear that. Anyway, I will find another alternative to complete my journey.

ASSISTANT: Thank you for contacting us, have a nice day.

USER: Thank you for the information.