You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I aid you?

USER: Can you help me to book a flight ticket on the name Gary Perez from DEN to NV - LAS?

ASSISTANT: Sure, may I know your departure and arrival dates?

USER: Ok, please book for the date Dec 27 and return date is Dec 29.

ASSISTANT: Can you please provide me your name?

USER: Please check above I have mentioned.

ASSISTANT: Do you have any class preference?

USER: No. There is one preference only and that is a direct flight.

ASSISTANT: Sorry, there are no direct flights on your route.

USER: That is ok, thank you for assisting me.

ASSISTANT: Thank you for reaching us.