You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: My name is Nancy Lopez.

ASSISTANT: How may I assist you?

USER: I want to book a flight ticket from MA - BOS to TX - DFW. Please help me in booking a flight ticket.

ASSISTANT: Sure, I am here to help you with that. May I know your travelling dates please?

USER: My travel dates are from 06/20 to 06/22.

ASSISTANT: Can you please tell me about the price that you can afford?

USER: I can afford up to 200.

ASSISTANT: Do you have any airline preference for booking your ticket?

USER: No, I am comfortable with any class.

ASSISTANT: Ok, please be on hold. I will check with it.

USER: Sure.

ASSISTANT: Sorry, there is no flight available as per your requirements.

USER: No problem, I wiil find my alternative. Thanks for your information.

ASSISTANT: Ok, thanks for reaching us.