You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I want to book a business class flight to reach Washington. Can you book a connecting flight for me?

ASSISTANT: Sure, I am here to help you for this. When are you planning your trip?

USER: I plan to travel on Feb 18 and return on Feb 20.

ASSISTANT: Can you please share me your airport codes?

USER: My source point is BOS and my destination is IAD.

ASSISTANT: May I know your name please?

USER: My name is Patricia Parker.

ASSISTANT: Sorry for inconvenience, no flights are found with your specifications.

USER: Ok, can you recheck is there is any flight available which depart in evening?

ASSISTANT: Sorry there are no flights in the evening.

USER: Ok, thank you for the details.

ASSISTANT: Thank you very much for approaching our agency.