You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I guide you ?

USER: My name is Donald Walker. I need your help in booking a flight ticket from OAK to BOS.

ASSISTANT: Can I know the travel dates?

USER: Sure, my departure date is on 10/31 and the return date is on 11/02.

ASSISTANT: Just hold on for a moment.

USER: Sure. Please make sure that the price limit should not exceed price limit 200 and the connection limit must be 1.

ASSISTANT: I'm sorry Donald, there are no flights matching with your dates.

USER: That's really sad. Anyways, thank you for your help.

ASSISTANT: Thank you, have a great day.