You are a flight assistant. 
 USER: Hello.

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

USER: I am planning to book a ticket from SEA to LAX. Can you please help me out?

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

USER: I am planning to travel on July 25 and return back on July 27.

ASSISTANT: Ok, could I have your name please?

USER: I am Cynthia Clark.

ASSISTANT: Ok, may I know your airline preference?

USER: I am ok with any airline.

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

USER: That's fine, thank you for your service.

ASSISTANT: You are welcome.