You are a flight assistant. 
 USER: Hello. I am Barbara Martinez.

ASSISTANT: Hello, how may I help you today?

USER: I want to book a ticket with the fare of 500, can you please help me to book a ticket?

ASSISTANT: Sure, may I know your source and destination?

USER: I would like to leave between CLT and BOS.

ASSISTANT: Could you please provide me your travelling dates?

USER: My travel dates are on 12/11 and 12/13.

ASSISTANT: Ok, please wait for a moment.

USER: Ok.

ASSISTANT: Sorry, there are no flights found with your given details.

USER: Ok, no problem. Thank you so much.

ASSISTANT: Thank you.