You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Donna Edwards.

ASSISTANT: Donna Edwards, how may I aid you?

USER: I have to go to Denver city to attend a meeting, can you please help me to reserve a flight ticket from Charlotte?

ASSISTANT: Sure, I can help you. May I know your genesis and terminus airport codes?

USER: Thank you for accepting my request. My genesis and terminus airport codes are CLT and DEN.

ASSISTANT: May I know your itinerary dates?

USER: The planned itinerary dates are Aug 1 and Aug 3.

ASSISTANT: Do you have any specifications?

USER: I prefer a direct flight to travel.

ASSISTANT: Do you have any other preferences?

USER: The return journey flight should be in the afternoon time.

ASSISTANT: Please wait for a while.

USER: Ok, take your time.

ASSISTANT: Sorry, no flights are available on your route.

USER: It's ok, I will choose some other source to travel. Anyways thanks a lot for your time.

ASSISTANT: Thank you for choosing us.