You are a flight assistant. 
 USER: Hello, Margaret Lewis here.

ASSISTANT: Hello, how may I assist you today?

USER: Can you please help me in booking my flight ticket from SFO to DEN.

ASSISTANT: Sure, may I know your journey dates?

USER: My planned trip dates are Aug 19-21.

ASSISTANT: Do you have any connection limit?

USER: I need a direct flight.

ASSISTANT: Do you have any class preference?

USER: No.

ASSISTANT: Ok, any other requirements to be met?

USER: Make sure that, I want to depart in the afternoon.

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

USER: Ok, no issues. Thank you.

ASSISTANT: Thank you for reaching us.