You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I serve you?

USER: Please help me to book a flight on Jan 23rd.

ASSISTANT: Sure, we are happy to help you.

USER: Thank you.

ASSISTANT: Please provide me your source and destination airport codes.

USER: My source and destination airports are BOS and DEN respectively.

ASSISTANT: When are you planning to return back?

USER: I will return back on Jan 25th.

ASSISTANT: Ok, is there any preference in connection?

USER: I prefer to travel with a connecting flight.

ASSISTANT: Ok, please wait a moment.

USER: Sure.

ASSISTANT: We are glad to inform you that Delta airlines is available for you at a price of 100 in economy class. Shall I proceed with the booking?

USER: Please proceed.

ASSISTANT: Can I have your name please.

USER: My name is Virginia Parker.

ASSISTANT: Your booking is done in flight number 1020.

USER: Thank you for your help.

ASSISTANT: Thank you for choosing our service.