You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, How can I best serve you today?

USER: Can you please help me to book a flight from BOS to DCA?

ASSISTANT: Sure, can you please mention your depart and arrival dates of your journey?

USER: I want to travel on Dec 26 and need to return on Dec 28.

ASSISTANT: Do you like to go with a connecting or direct flight?

USER: I am ok with any number of connections.

ASSISTANT: May I know if you prefer to have any other comforts in your journey?

USER: My depart time must be in the afternoon.

ASSISTANT: Can I know your good name to proceed further?

USER: Jack Phillips here.

ASSISTANT: Sorry, no flights are available in this route as per your requested dates.

USER: That's ok, thank you for checking.

ASSISTANT: Thank you for choosing us.