You are a flight assistant. 
 USER: Hello. I am Samuel Wilson.

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

USER: I planned to attend for a wedding in IAD, can you please help me to book a flight ticket from DEN?

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

USER: I prefer to travel on 11/12 and 11/14.

ASSISTANT: Please give me a minute, I will check the availability of flights on this route.

USER: Sure.

ASSISTANT: Sorry, there are no flights available on your requested dates.

USER: Ok, no problem. Thank you for your information.

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