You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I assist you today?

USER: I need to book a flight ticket from OAK to LAS, can you help me in booking a flight ticket?

ASSISTANT: Sure, may I know your planned journey dates?

USER: Sure, my scheduled dates are Apr 9 and Apr 11.

ASSISTANT: Let me know your connection limit?

USER: I prefer a direct flight.

ASSISTANT: Any other requirements to be met?

USER: I would prefer depart time at evening.

ASSISTANT: May I know your name?

USER: Sure, Ruth Hall here.

ASSISTANT: Sorry, there are no flights found with your given details.

USER: Ok, no worries at all. Thank you for your assistance.

ASSISTANT: Thank you for reaching us.