You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Katherine Phillips.

ASSISTANT: What service that you are looking from our agency?

USER: I would like to book a ticket from IAD to LAS,can you please help me out?

ASSISTANT: Sure, I am glad to help you with that. Can you please provide your planned dates of travelling?

USER: I am travelling on these dates 02/28 and 03/01.

ASSISTANT: Please wait a moment to check the flights.

USER: Sure.

ASSISTANT: We regret to inform you that, there are no flights moving to your region with your planned dates of travelling.

USER: Ok no problem, thank you for your services.

ASSISTANT: Thank you for reaching us, have a great day.