You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I aid you today?

USER: Myself Steven Adams.

ASSISTANT: Nice meeting you Adams.

USER: I have to go Las Vegas for my film shooting purpose, can you please book a flight ticket for me?

ASSISTANT: Sure, we are gleeful to help you. Can you please provide your nearest airport codes for booking?

USER: Thanks, I want to fly from IAD airport and destination airport is LAS.

ASSISTANT: Ok, may I know your preferable dates of travelling?

USER: My departure date is 06/21 and please book my return ticket also on 06/23.

ASSISTANT: Please wait a moment to check the flights.

USER: Ok.

ASSISTANT: Sorry to inform you that, there are no flights moving to your region with your travelling dates.

USER: Oh! It's ok no problem, I will go with another airline service. Thank you for your information.

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