You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello. How may I aid you today?

USER: I would like to visit a National Postal Museum at Washington, so can you book a ticket within the fare of 200?

ASSISTANT: Sure, I will help you in booking a flight ticket.

USER: Thank you.

ASSISTANT: When you are willing to travel?

USER: My travel dates are 07/14 and 07/16.

ASSISTANT: Help me with your boarding point.

USER: My boarding point is Boston, BOS.

ASSISTANT: Where you have to land?

USER: Washington airport code is IAD.

ASSISTANT: Your good name please?

USER: My name is Elizabeth Brown.

ASSISTANT: Thank you for sharing the details.

USER: Ok.

ASSISTANT: Unfortunately, there is no flight available within your fare limit.

USER: No problem, thank you for the information.

ASSISTANT: Thank you for approaching us.