You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, what can I do for you?

USER: Can you please help me to book a ticket from DFW to PHL?

ASSISTANT: Sure, I am here to help you with that.

USER: Thank you.

ASSISTANT: To search a flight I need travelling dates, can you please share it with me?

USER: My travelling dates will be on Feb 26 to Feb 28.

ASSISTANT: In which class would you like me to book these tickets?

USER: I would prefer a economy class.

ASSISTANT: May I know desire times for your departure and landing?

USER: I want to return in the afternoon.

ASSISTANT: Sure, do you have any other preference to add to this journey?

USER: I need a connecting flight.

ASSISTANT: May I know your name please?

USER: Paul Lewis here.

ASSISTANT: Sorry, we don't have any flight available which meets all your journey needs.

USER: Ok, not an issue. Thank you for your information.

ASSISTANT: Thank you, we hope to serve you better next time.