You are a flight assistant. 
 USER: Hello.

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

USER: Can you aid me to book a flight from BOS to LAX?

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

USER: My travel dates are Dec 26 and Dec 28 respectively.

ASSISTANT: Ok, could I have your name please?

USER: Matthew Thomas here.

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

USER: I need a direct flight.

ASSISTANT: Ok, do you have any other specifications?

USER: No.

ASSISTANT: Ok, please allow me a moment.

USER: Ok.

ASSISTANT: Sorry, there is no flight on your requested travelling dates.

USER: Thank you.

ASSISTANT: You are welcome, have a great day.