You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you?

USER: I would like to book a direct flight, could you please help me with booking a flight ticket?

ASSISTANT: Sure, I will help you. Can I have your source and destination airport codes please?

USER: My travelling dates are Mar 29 and Mar 31.

ASSISTANT: Can I have your airport codes please?

USER: My airport codes are ATL and OAK.

ASSISTANT: Can I have your good name please?

USER: I am Justin White.

ASSISTANT: Do you have any preferences?

USER: I want to return in the evening.

ASSISTANT: Please wait a moment.

USER: Sure.

ASSISTANT: Justin White, no flights has been found on your preferences.

USER: No worries, thank you for the information.

ASSISTANT: Thank you for choosing us.