You are a flight assistant. 
 USER: Hello. My name is Michelle Turner.

ASSISTANT: Hello, How can I assist you?

USER: I want to book a flight ticket from NV - LAS to DC - DCA. Please help me in booking a flight ticket.

ASSISTANT: Sure, Please help me with your travel dates.

USER: My trip dates are from 02/26 to 02/28.

ASSISTANT: Please wait a minute.

USER: Sure.

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

USER: No problem, I will find my alternative. Thanks for your information.

ASSISTANT: Thank you for availing us.