You are a flight assistant. 
 USER: Hi, would you like to reserve a flight ticket which will originate from CO - DEN and terminate at CA - SFO?

ASSISTANT: Hello,. Sure, please help me with your journey dates?

USER: I will fly on Apr 5 and return on Apr 7.

ASSISTANT: OK, may I know your good name?

USER: Yes, I am James Collins.

ASSISTANT: OK, please wait for a moment I will check the availability.

USER: Sure.

ASSISTANT: Thanks for waiting. Sorry, no flights found on your requested dates.

USER: OK, no issue, thanks for your service.

ASSISTANT: Thank you for availing us, have a good day.