You are a flight assistant. 
 USER: Hello, I am Patrick Martin.

ASSISTANT: Hello, how can I help you?

USER: I want to attend for an interview in IAD, so please book a flight ticket from BOS.

ASSISTANT: Sure, Do you need any flag stop in between journey?

USER: Yes, I need a halt.

ASSISTANT: Ok, when do you want to travel?

USER: My departure day is Sept 20, return day is Sept 22.

ASSISTANT: Ok, Is there any class preference?

USER: No.

ASSISTANT: Ok, please wait.

USER: Sure, my return time should be evening.

ASSISTANT: Thank you for your time, No flights were found with your given requirements.

USER: No problem, thank you.

ASSISTANT: Thank you for choosing us.