You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, do you need any help from us?

USER: I need to travel SEA and PHL, can you please reserve flight ticket ?

ASSISTANT: Sure, could you please share your departure and arrival day?

USER: My travelling dates are Dec,15 and Dec,17.

ASSISTANT: Ok, could I have your name please?

USER: Myself Ruth Taylor.

ASSISTANT: Ok, do you need direct or connecting flight?

USER: I need direct flight ticket.

ASSISTANT: Ok, may I know your class preference?

USER: I need economy class flight ticket.

ASSISTANT: Ok, please allow me a moment.

USER: Sure.

ASSISTANT: Sorry, there is no flight with your request.

USER: Oh! Sad to hear that. Anyway, I will find another alternative to complete my journey. Thank you for the information.

ASSISTANT: You are welcome.