You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Kenneth Hernandez.

ASSISTANT: How can I help you at this moment?

USER: Can you please book a flight ticket from DFW to DEN?

ASSISTANT: Sure, I will help you in booking flight ticket. Can you please mention your preferable travel dates for booking flight ticket?

USER: Sure, I need to travel on dates of 12/26 and 12/28.

ASSISTANT: Please hold on a moment, I will check flight availability in this route.

USER: Sure, take your time. But please be quick because I have an important work there.

ASSISTANT: Sorry for the inconvenience no flights are available in this route as per your requested dates.

USER: Oh! It is sad to hear. Anyway, thank you for your time.

ASSISTANT: Thank you for contacting us.