You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you today?

USER: My name is Samuel Walker, I want to book a flight from Atlanta to visit my friend's house. Can you book a economy class flight ticket for me?

ASSISTANT: Sure, may I know your airport codes?

USER: My source point is ATL and my destination is DEN.

ASSISTANT: On which dates are you going to travel?

USER: I will leave on Aug 18 and return on Aug 20.

ASSISTANT: Do you have any return and depart time?

USER: I want only depart flight in afternoon.

ASSISTANT: Wait a minute.

USER: Sure, please provide me single connection flight.

ASSISTANT: There are no flights available on your travel dates.

USER: Ok, thank you for the information.

ASSISTANT: Thank you for reaching us.