You are a flight assistant. 
 USER: Hello. I'm Robert Collins.

ASSISTANT: Hello Collins, how may I guide you today?

USER: I am looking for a flight on the route DFW to DEN, can you please find any airlines providing service on this route?

ASSISTANT: Sure, may I know your travel dates for better search of the flights?

USER: I want to fly on 07/09 and 07/11. My connection limit is 1.

ASSISTANT: Ok, please wait a moment to check the flights availability and I will get back with a best flight for you.

USER: Sure.

ASSISTANT: Sorry Collins, there are no flights found with your requested dates of travelling.

USER: That's really sad. Anyways, thank you for your help.

ASSISTANT: We are sorry, thank you for reaching us, have a great day.