You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you today?

USER: Could you please book me a plane ticket from OAK to LAS?

ASSISTANT: Sure, help me with the trip dates?

USER: I am planning to start on Nov 15th and return on Nov 17th.

ASSISTANT: May I know your name please?

USER: I am James Clark.

ASSISTANT: Do you have any connection limit?

USER: Yes, I need 1 lay by.

ASSISTANT: Let me know your other specifications to be met?

USER: My depart time must be in the evening.

ASSISTANT: Sorry, no flights were available at this moment.

USER: That's alright, thanks for your assistance.

ASSISTANT: Thank you for reaching us.