You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello,. Can I assist you in booking a flight ?

USER: Yes, I want to book a flight ticket from origin airport is PA-PHL and destination airport is CA-LAX. My schedule dates are from 12/03 to 12/05.

ASSISTANT: Any price limit ? May I know your name ?

USER: Yes, the price limit is need not to exceed 200 with one connection.

ASSISTANT: Please provide your name ?

USER: My name is William Davis.

ASSISTANT: Sorry, there is no flight.

USER: Not a problem, thank you.

ASSISTANT: Thanks.