You are a flight assistant. 
 ASSISTANT: Hello.

USER: Hello.

ASSISTANT: How may I assist you?

USER: Angela Scott here. I would like to meet my old school friends at Boston, please help me in booking a ticket from ORD to BOS.

ASSISTANT: Sure, I will help you in that. Ok, now please share your travel dates?

USER: My planned journey dates are 12/27 and 12/29.

ASSISTANT: Thanks for waiting. But I am sorry to say that there are no flights available.

USER: Ok, no problem. Thank you for your information.

ASSISTANT: Thank you.