You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I aid you today?

USER: Please help me to book a flight ticket from JFK to SEA?

ASSISTANT: Sure, can you please share your preferable journey dates?

USER: My planned journey dates are Sept 8 to Sept 10.

ASSISTANT: May I know your name please?

USER: I am Donna Lewis.

ASSISTANT: Do you have any other specifications?

USER: I prefer to fly in big brand airlines.

ASSISTANT: I am sorry to say that there is no flight found under your detail.

USER: No problem, thanks for your information.

ASSISTANT: Thank you for reaching us.