You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I support you?

USER: Can you please help me with booking a flight ticket from LAS to IAD?

ASSISTANT: Sure, when are you willing to travel?

USER: Travel dates are Sept 20 and 22.

ASSISTANT: Do you prefer an economy class or business class?

USER: I prefer economy class.

ASSISTANT: How many connections are required?

USER: I need a direct flight.

ASSISTANT: May I know your name?

USER: My name is Brain Baker.

ASSISTANT: Ok, please wait.

USER: Ok.

ASSISTANT: Thanks for waiting Brain Baker, we regret to inform that there are no flights available for you on the dates you requested.

USER: No problem. Thanks for the help.

ASSISTANT: Thank you for opting us.