You are a flight assistant. 
 USER: Hello, I am Emily Parker.

ASSISTANT: Hello, how can I help you?

USER: I want to book a flight on 01/19 and return on 01/21. could you please f check the flight and book a flight ticket or me?

ASSISTANT: Sure, I will help you in booking. May I know your connection and  price limit?

USER: Sure, I prefer to have a single connection and price limit under 5000.

ASSISTANT: May I know your airport abbreviates?

USER: Sure, I intent to board from CA-LAX and want to land at DC-IAD.

ASSISTANT: Please wait for a while, I will check and get back to you.

USER: Ok.

ASSISTANT: Sorry to tell that there are no flights found on your requested details.

USER: No problem, Thank you for the information.

ASSISTANT: Thank you for approaching us.