You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I am Brenda Baker, can you reserve a ticket from Washington, IAD to Las Vegas, LAS.

ASSISTANT: Sure, let me know your preferable dates?

USER: My travelling dates are on 06/29 and 07/01.

ASSISTANT: Sorry, there are no flights available for given schedule.

USER: Ok, thank you for informing me.

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