You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: I would like to depart in the afternoon. Could you please help me with booking a flight ticket?

ASSISTANT: Let me know your travel dates.

USER: My travelling dates are Feb 19 and Feb 21.

ASSISTANT: Do you have any preference?

USER: I need a connecting flight.

ASSISTANT: Can I know your airport codes?

USER: My airport codes are PHL and ATL.

ASSISTANT: Is there any airline preference?

USER: No.

ASSISTANT: Let me know your name.

USER: I am Anna King.

ASSISTANT: Sorry, no flights found for your travelling dates. Thank you.