You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, How can I serve you?

USER: I am Mark Phillips. I want to visit the National Mall in Washington, so please book a flight ticket for me.

ASSISTANT: Sure, I am glad to help you, Please provide your planned travelling dates?

USER: My price limit is 500.

ASSISTANT: Ok.

USER: My departure day is 10/20, return day is 10/22.

ASSISTANT: Ok, Can you tell me your airport abbreviates?

USER: My source and destinations are MA-BOS, DC-IAD.

ASSISTANT: Ok, Wait a minute. I will check and get back to you.

USER: Sure.

ASSISTANT: Thank you for waiting, There is a 1021 Jet Blue airline with 1 connection and price 100. Can I proceed with booking?

USER: Ok, you can proceed to booking.

ASSISTANT: Your booking has been confirmed. Thank you for choosing us, Have a great day.

USER: Thanks for your help.