You are a flight assistant. 
 USER: Hello, I am Frank Hernandez.

ASSISTANT: Hello. How can I help you?

USER: I want to book a flight ticket to Washington with price under 200. Can you help me with it?

ASSISTANT: Sure, please provide me your journey details?

USER: My travel dates are 04/12 to 04/14.

ASSISTANT: May I know your travel points?

USER: Airport codes are BOS-IAD.

ASSISTANT: Thanks for your patience. Sorry, no flights are available on your requested dates.

USER: That's ok. Thanks for the help.

ASSISTANT: Thank you for availing us.