You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you?

USER: I am Barbara Clark. Please book a flight ticket to Boston on 09/09 and return on 09/11.

ASSISTANT: Sure, may I know your journey codes?

USER: I am heading to Boston, BOS from Philadelphia, PHL.

ASSISTANT: Do you need any halt in between the journey?

USER: Yes, I need a halt in between my journey.

ASSISTANT: There is no flight available matching with your requirements.

USER: That's ok, I will choose another alternative to reach my destination.

ASSISTANT: Thanks for availing us.