You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you ?

USER: My name is Angela Green and I want to book the flight ticket from DFW to ORD. Can you please help me?

ASSISTANT: Sure, I can help you. please provide me your travel dates.

USER: My travel dates are 04/17 and 04/19.

ASSISTANT: Ok, please provide me your class preference.

USER: No class preferences.

ASSISTANT: Ok, do you have any other requirements?

USER: I would like to return in the afternoon. I need single connection.

ASSISTANT: Sorry, there is no flight available as per your requirements.

USER: Ok, thank you for the information.

ASSISTANT: You are most welcome and have a nice day.