You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, How can I serve you?

USER: I want to book a ticket from DEN to LAS. Could you book a ticket?

ASSISTANT: Sure, May I know the trip dates?

USER: Travelling dates are Oct,  24 and Oct, 26.

ASSISTANT: May I know your name?

USER: I am Kathleen Harris.

ASSISTANT: Please wait a moment.

USER: Ok.

ASSISTANT: Sorry, No flights found with your chosen dates.

USER: Thanks.

ASSISTANT: Thank you for opting us.