You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you today?

USER: I am Gregory Walker. I want to book a ticket from DEN to SEA, can you please book a ticket?

ASSISTANT: Sure, we are pleased to serve you. May I know your itinerary dates?

USER: My trip dates are on Feb 09 and Feb 11.

ASSISTANT: Is there any class preference for you?

USER: No.

ASSISTANT: Can you share me your departure time and arrival time?

USER: My depart time is at afternoon.

ASSISTANT: Do you need any way station in your journey?

USER: Yes, I need single stopover.

ASSISTANT: Sorry to inform you that, there are no flights available with your requirements.

USER: Ok, thank you for informing me.

ASSISTANT: Thank you for choosing us.