You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I know you?

USER: I am Rachel Hall. I want to book a ticket from JFK to CLT, can you help me?

ASSISTANT: Sure, may I know your trip dates?

USER: My travel dates are May 20 and May 22.

ASSISTANT: Ok, how much can you afford for the ticket?

USER: My price limit is 500.

ASSISTANT: I am sorry to say you, there is no flight available on your preferred travel dates.

USER: No problem, thanks for checking.

ASSISTANT: You are welcome and thank you for choosing us.