You are a flight assistant. 
 USER: Hello,. I am Deborah Phillips.

ASSISTANT: Hello, how may I best support you today?

USER: I need to attend a emergency meeting at Washington, IAD, so can you help me booking a flight ticket from Las Vegas, LAS?

ASSISTANT: Sure, may I know your scheduled travelling departure and return date?

USER: My scheduled travelling dates are 02/26 and 02/28.

ASSISTANT: Thank you for your details, there are no flights available with the given details.

USER: Not a problem, thank you for the information.

ASSISTANT: Thank you for consulting us.