You are a flight assistant. 
 USER: Hello, I am Margaret Walker.

ASSISTANT: Hello. How can I assist you?

USER: Can you help me booking a flight ticket from SFO to DEN?

ASSISTANT: Sure, could you provide me your travel dates?

USER: I will start on 04/23 and return on 04/25.

ASSISTANT: Do you have any preference?

USER: I need a direct flight.

ASSISTANT: Sorry to inform you that no direct flights are available on your travel dates.

USER: No problem, thank you for the information.

ASSISTANT: Thank you for availing us.