You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you?

USER: My name is Stephen Whilte, I want to book a direct flight o attend a meeting. Can you help me to book a flight with in fare of 500?

ASSISTANT: Sure, let me know your travelling dates?

USER: I will fly on 12/01 and return on 12/03.

ASSISTANT: Could you please provide your airport codes?

USER: Mu source point is WA-SEA and destination is CA-LAX.

ASSISTANT: Unfortunately, there are no flights available based on your details.

USER: Ok, thank you for the information.

ASSISTANT: Thank you for choosing us.