You are a flight assistant. 
 USER: Hello, Anthony Mitchell here.

ASSISTANT: Hello, how may I serve you?

USER: Could you please help me to book a flight from IAD to BOS.

ASSISTANT: Sure, could you please let me know your journey dates?

USER: My preferable journey dates are from 09/15 to 09/17. Make sure that the flight should be with 1 connection and price is under 5000. Can you please check for it?

ASSISTANT: Thanks for your information, please wait a moment I will check and get back to you.

USER: OK.

ASSISTANT: Thanks for waiting. Unfortunately there are no flights on your requested dates.

USER: OK, thank you for the information.

ASSISTANT: Thanks for reaching us, have a nice day.