You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you today?

USER: I have planned to attend for a Sports event in Las Vegas, NV - LAS. Can you please book a ticket from Washington, DC - IAD?

ASSISTANT: Ok, let me know your travel dates.

USER: I will depart on 12/16 and return on 12/18.

ASSISTANT: Can I know your good name?

USER: Sure, I am Carol Parker.

ASSISTANT: Ok, wait a minute.

USER: Sure.

ASSISTANT: Currently no flights are available to your destination point.

USER: Ok, no issues. Thank you.

ASSISTANT: Thank you for choosing us.