You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you?

USER: Can you help me out with the flight ticket booking from DTW to DEN?

ASSISTANT: Sure, may I know your planned travel dates please?

USER: Ok, please book for the dates Apr 29 and May 1st respectively.

ASSISTANT: Would you like to travel in a connecting flight or a direct flight?

USER: Ok, please can I know if there is a connection flight?

ASSISTANT: Do you have any particular time for departing and returning?

USER: Ok, please check for the depart time afternoon.

ASSISTANT: May I know your good name please?

USER: My name is David Mitchell.

ASSISTANT: Sorry, there is no flight available on your requested dates.

USER: That is ok, thank you for assisting me.