You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Steven Moore here.

ASSISTANT: How may I assist you?

USER: I am planning to book a flight ticket to IAD from LAS, can you do it for me?

ASSISTANT: Sure, I will help you for booking. May I know your travelling dates?

USER: From 06/10 to 06/12. Do you find any flight for me?

ASSISTANT: Sorry Moore, there is no flight available for you.

USER: It's ok, thank you.

ASSISTANT: Welcome. Thank you for choosing us.