You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I guide you?

USER: My name is Rachel Martin, and I want to book a ticket from NV-LAS to DC-IAD.

ASSISTANT: OK,can I know the dates of travel?

USER: Sure, my dates of travel is from 10/07 to 10/09.

ASSISTANT: Hold on for a moment.

USER: Sure.

ASSISTANT: Do you have any additional requirements?

USER: Yes, my connections limit is 0 of cost 200. Do you find any ticket for me?

ASSISTANT: I'm sorry Rachel, there are no flights matching your requirements.

USER: It sounds bad for me anyways thanks, for your information.

ASSISTANT: Thank you, have a good day.