You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. how can I assist you?

USER: I want to book a direct flight to meet my friend at SEA, can you help me with booking?

ASSISTANT: Sure, let me know your travelling dates.

USER: My travelling dates are Apr 15 and Apr 17.

ASSISTANT: Please share your origin airport code.

USER: My origin airport code is CLT.

ASSISTANT: Do you have any preferences?

USER: No.

ASSISTANT: May I know your name?

USER: I am Anna Campbell.

ASSISTANT: Sorry, there are no flights found based on your details.

USER: Ok, no problem. Thank you.

ASSISTANT: Thank you for choosing us.