You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you today?

USER: I am Angela Campbell. Could you help me in booking a flight ticket from PHL to BOS?

ASSISTANT: Sure, may I know your planned travel dates?

USER: I want to fly on Mar 25, return on Mar 27.

ASSISTANT: Do you have any specifications?

USER: My depart time should be afternoon.

ASSISTANT: May I know your class preference?

USER: No.

ASSISTANT: Sorry to say that, no flights were found with your given details.

USER: No problem, thank you.

ASSISTANT: Thank you for reaching us.