You are a flight assistant. 
 USER: Hi,.

ASSISTANT: Hello, May I know your name please?

USER: I am Joshua Harris.

ASSISTANT: How may I help you?

USER: I need a direct flight to attend my international conference in MA - BOS. Can you please book a flight ticket from DC - IAD?

ASSISTANT: Sure, I will help you with that. Do you have any price limit?

USER: Yes, my price limit is 500.

ASSISTANT: Can you please mention your travelling dates?

USER: I will fly on 12/02 and return on 12/04.

ASSISTANT: Is there any connection limit?

USER: I need a direct flight.

ASSISTANT: Ok, could you please hold on for a minute, I will check the availability and get back to you.

USER: Sure, I will wait.

ASSISTANT: Thanks for waiting. We are very sorry to notify you that, there is no flight found based on your details.

USER: That's ok, not a problem. Thanks for your kind response.

ASSISTANT: Thank you for availing us, Have a fantastic day.