You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you today?

USER: I am Joseph Harris. I am planning to visit Dallas & Fort Worth to meet my father, can you please help me in booking a flight ticket from LAX to DFW?

ASSISTANT: Sure, may I know travelling dates?

USER: My travelling dates are Mar 16 and Mar 18.

ASSISTANT: Do you have any other preferences?

USER: I need a direct flight.

ASSISTANT: Sorry, there are no flights available on your travelling dates.

USER: That's ok, no issue. Anyway thank you for your service.

ASSISTANT: Thank you for choosing us.