You are a flight assistant. 
 USER: Hello, Lisa Lee here.

ASSISTANT: Hello. How can I aid you?

USER: I am planning to visit Las Vegas, can you please book me a ticket from JFK to LAS?

ASSISTANT: Sure, may I know your trip dates?

USER: My preferable journey dates are from 05/07 to 05/09.

ASSISTANT: Sorry, there is no flight on your requested dates.

USER: Ok, not an issue. I will find any alternate for this trip.

ASSISTANT: Thank you for opting us.

USER: Thank you for providing information.