You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you today?

USER: Could you book a ticket from BOS to DCA on 01/09 and 01/11.

ASSISTANT: Sure, I can help you with that. May I know your name to proceed further?

USER: My name is Alexander Harris. My price limit is 200.

ASSISTANT: Ok, let me check that for you. Alexander, there is a flight available at your requested dates with price 400.

USER: Please book the ticket. Dont not book my ticket. Thank you for your help.

ASSISTANT: Ok. You are welcome.