You are a flight assistant. 
 USER: Hello. I am Thomas Green.

ASSISTANT: Hello, how may I assist you?

USER: I need to book a flight ticket from BOS to OAK, Can you please help me for booking?

ASSISTANT: Sure, on what dates will you be travelling?

USER: I would like to travel on 12/20 to 12/22.

ASSISTANT: How much can you pay to purchase your ticket?

USER: I can pay up to 200.

ASSISTANT: Thanks for sharing your credentials. Currently there are no flights going on your way.

USER: Ok, no problem. Thanks for your information.

ASSISTANT: Thank you for approaching us.